HEP Phenomenology·hep-ph

Fri·Jul 31, 2026Friday·July 31, 2026

46 papers—21 primary·25 cross-listed

01
A Material Frame: Hard Recoils from Slow Force Carriers
Francesco Serra🇺🇸
We modify the Standard Model by making the longitudinal component of the photon physical, propagating with small speed $c_{L} ≪ 1$ . This modification breaks gauge invariance and Lorentz symmetry, defining a preferred reference frame. No new fields or scales are introduced, and the photon mass is protected by a Galilean higher-form symmetry. The theory has a smooth $c_{L} \to 0$ limit: the new modes decouple from standard matter and ordinary gauge theory predictions are recovered. Experimental constraints are severe. Charged particles Cherenkov-emit these slow modes, experiencing hard recoils against the preferred frame. The recoil rate decreases with $c_{L}$ , but the momentum transfer remains of the order of the particle's momentum. Dark matter detectors, sensitive to keV-scale nuclear recoils, imply an order-of-magnitude bound $c_{L} ≲ 1 0^{- 60}$ , tens of orders of magnitude stronger than speed-difference bounds. At such values, $c_{L}$ is better understood as a recoil-rate factor rather than a physically relevant speed. The slow modes, practically fixed in space, make the reference frame a material medium capable of absorbing momentum from charged particles.
hep-phhep-th0 citations
02
Suppressed Quantum Effects of Weakly Coupled Waves
Yunjia Bao🇺🇸 · Dhong Yeon Cheong🇰🇷 · Nicholas L. Rodd🇺🇸 · Joey Takach🇺🇸 · Lian-Tao Wang🇺🇸 · Kevin Zhou🇺🇸
Precision experiments increasingly target weakly coupled waves, including axion dark matter and gravitational radiation. Such waves are commonly described as classical fields, yet they could exist in quantum states with no classical counterpart. We exhibit two severe obstructions to detecting nonclassical effects, both independent of the mode occupancy. First, realistic detectors cannot resolve the fundamental modes of a field; instead they couple to coarse-grained "effective" modes, which often washes out nonclassical effects. Second, all nonclassical effects are suppressed by extra powers of the weak coupling, making them much harder to detect than the waves themselves. We prove this in general, and explicitly show how the suppression arises for quadrature and number statistics, entanglement, and decoherence. The suppression can in principle be overcome given suitable quantum resources, such as highly squeezed detector states, but the required parameters are far beyond current experimental capabilities. We use the axion cavity haloscope as an explicit example, although our conclusions apply to many ultralight dark matter searches, and rule out proposals to establish the quantization of gravity from observations of gravitational waves.
hep-phgr-qchep-exhep-th+12 citations
03
The Dark Dimension meets the Axiverse
Kevin Langhoff🇺🇸 · Maria Ramos🇨🇭 · Mario Reig🇨🇭
We explore the cosmological implications of combining dark dimension scenarios with an axiverse. If gauge sectors are realized on branes, towers of Kaluza-Klein (KK) excitations of closed string axions can propagate through the dark dimension in addition to the tower of graviton excitations. This modifies cosmology in two ways. First, if any of these axion towers interact with the standard model (SM) plasma, they can significantly alter the freeze-in production of the cosmological abundance of tower states. Freeze-in to graviton and axion towers can provide all of dark matter (DM) for an axion decay constant in $1 0^{12} GeV ≲ f_{a} ≲ 1 0^{16} GeV$ and reheating temperatures $5 MeV ≲ T_{RH} ≲ O (1) GeV$ . Second, different towers fragment into each other and redistribute energy; each tower's fraction of energy at late times is fixed by their interactions. If there are $N ≫ 1$ axion towers, the energy visibly injected into the SM by any decaying tower is diluted by a factor of $N$ . This suppression offers a simple realization of how dark dimension dark matter can avoid strong cosmological constraints which rule out the simplest models. In the process of this exploration we develop a continuum approach to evaluating tower fragmentation which offers insight and aids numerical calculations by reducing the problem to quadrature.
hep-phhep-th0 citations
04
The Very Nearly Right Theory of Flavor
Nima Arkani-Hamed🇺🇸 · Carolina Figueiredo🇺🇸 · Lawrence J. Hall🇺🇸 · Claudio Andrea Manzari🇺🇸
A striking empirical observation about the CKM matrix is that the angles of the unitarity triangle $(α, β, γ)$ are very close to $(π /2, π /8, 3 π /8)$ , simple fractions of $π$ that are suggestive of an underlying theory linking flavor and spontaneous CP violation. However, relating this empirical observation to an underlying theory of flavor is challenging, since the unitarity triangle is a complicated function of the Yukawa matrices. In this letter we present a simple picture for the Yukawas where this direct link is possible. We begin by parametrizing the ten-dimensional space of flavor data via "nine-link textures", full-rank $Y_{u, d}$ matrices with a total of nine non-zero entries, with a single CP violating phase. Fitting the ten parameters of all such textures to the flavor data reveals a wonderful surprise: the CP phases cluster tightly around multiples of $π /8$ ! This happens because the entries of $Y_{u, d}$ naturally define a "Yukawa triangle", in most cases identical to the unitarity triangle at leading order in small flavor parameters. Most interestingly, these two triangles are not the same beyond leading order, yielding precise predictions for $(α, β, γ)$ with calculable deviation from $(π /2, π /8, 3 π /8)$ , which can be decisively excluded or strongly confirmed by the next generation of experimental measurements of the angles. The 9-link textures are sparse and their determinants are naturally real, which taken together with spontaneous CP violation can resolve the strong CP problem.
hep-phhep-exhep-th1 citation
05
The inseparable three and four tops
Gauthier Durieux🇧🇪 · Hesham El Faham🇬🇧 · Rikkert Frederix🇸🇪 · Davide Pagani🇮🇹 · Marco Zaro🇮🇹
In measurements of four-top-quark production ( $tttt$ ), LHC collaborations observe a significant degeneracy with three-top-quark production. We compute the dominant three-top-production mode, namely associated production with a $W$ boson ( $ttt W$ ), at complete next-to-leading order (NLO), including all possible QCD and electroweak (EW) corrections. Beyond leading order (LO), $ttt W$ production with the radiation of an additional $b$ -flavoured quark contributes to the same final state as $tttt$ production with a $t \to bW$ decay. Away from the on-shell top-quark limit, the usual overlap removal of resonant contributions in the non-resonant computation either breaks gauge invariance and generates unitarity violation or involves a significant arbitrariness in the required reshuffling of momenta. To overcome these issues, we introduce a novel window-removal prescription that produces consistent predictions for the inseparable $ttt W + tttt$ process, with both components described at NLO accuracy. We argue that such a joint prediction should be used in comparisons with experimental selections targeting $tttt$ production, since the on-shell $tttt$ component can not be isolated in practice. Such a joint prediction has an inclusive rate more than 10% higher than the purely on-shell $tttt$ one. We also study an idealised veto on additional hard and central $b$ -jet radiation, which suppresses the contributions of resonant $tttt$ diagrams as well as their interference with non-resonant $ttt W$ ones and therefore defines a relatively pure $ttt W$ -like signal region. Formally subleading coupling orders are numerically important at LO, while the corresponding subleading NLO corrections largely cancel both inclusively and differentially. Consequently, the complete-NLO prediction is well approximated by retaining the first three LO coupling orders together with the leading QCD NLO correction.
hep-phhep-ex0 citations
06
Seesaw Cosmology
Nicolás Bernal🇦🇪 · Chee Sheng Fong🇧🇷 · Óscar Zapata🇨🇴
We study perturbative reheating in which the inflaton transfers its energy to the Standard Model through right-handed neutrinos (RHNs) responsible for light-neutrino masses via the type-I seesaw mechanism. We refer to the resulting nonstandard thermal history as $sees a w$ $cos m o l o g y$ . When produced relativistically and sufficiently long lived, the RHNs generate a characteristic sequence of inflaton, relativistic-RHN, nonrelativistic-RHN, and Standard Model radiation domination. We solve the Boltzmann system while retaining the production-time dependence of the nonthermal RHN distribution and its relativistic-to-nonrelativistic transition. The Standard Model temperature rapidly approaches a plateau during inflaton domination and subsequently scales as $a^{- 1/4}$ and $a^{- 3/8}$ during relativistic- and nonrelativistic-RHN domination, respectively. We investigate the implications of seesaw cosmology for dark-matter production. Direct production through inflaton decays can be enhanced relative to conventional reheating by a factor of order $m_{ϕ} / (2 m_{N})$ , while ultraviolet freeze-in exhibits the critical temperature powers $p = 12$ and $20$ , leading to potentially large contributions before the final radiation-dominated era. Seesaw cosmology therefore connects neutrino-mass generation, the pre-BBN thermal history and phenomena such as dark-matter production and baryogenesis.
hep-phastro-ph.CO0 citations
07
Precise predictions for double Higgs production in association with a vector boson in Effective Field Theory
Ramona Gröber🇮🇹 · Michał Ryczkowski🇮🇹 · Gioia Sacchi🇮🇹
We present next-to-next-to-leading order (NNLO) QCD predictions for Higgs boson pair production in association with a weak gauge boson, $pp \to V hh$ with $V = W^{\pm}, Z$ , in effective field theory descriptions of new physics. We consider both the Standard Model Effective Field Theory (SMEFT), truncated at dimension six, and the Higgs Effective Field Theory (HEFT) at leading order in the chiral expansion. The calculation builds on the factorisation of the quark-induced production process into Drell-Yan production of an off-shell vector boson and its subsequent decay into $V hh$ , supplemented in the $Z hh$ channel by the loop-induced $g g \to Z hh$ contribution that first enters at NNLO QCD. We provide inclusive predictions at $s = 13.6$ and $14.0$ TeV, including scale, PDF, and $α_{s}$ uncertainties, and express the results in terms of numerical coefficients that allow fast evaluations for arbitrary EFT parameters in the considered ranges. We find that, for $W^{\pm} hh$ production, QCD corrections largely factorise from the EFT dependence, leading to almost flat $K$ -factors. In contrast, $Z hh$ production shows a stronger dependence on the EFT coefficients because of the gluon-induced component.
hep-phhep-ex0 citations
08
Photon-Tagged Energy Flow in Inclusive Endpoint $B$ Decays
Shuai Zhao🇨🇳
We introduce a $B$ -decay tagged energy correlator (BTEC) to resolve the angular structure of energy flow in inclusive $B$ decays in the endpoint region, focusing on the direct-photon contribution to $B \to X_{s} γ$ . At leading power and at the natural collinear angular scale $τ \sim s \sim Q Λ_{QCD}$ , we derive a factorization relation involving the standard hard coefficient and $B$ -meson shape function together with a new measured quark jet function; no new leading-power nonperturbative function is introduced. We calculate the measured jet function at one-loop accuracy and verify that its angular integral reproduces the standard inclusive quark jet function. For the central Bosch--Lange--Neubert--Paz parameter set, an illustrative benchmark gives $3 - 16%$ migration outside the fixed angular cuts $τ_{c} = 2 - 4 GeV^{2}$ . With an independently constrained shape function, the angular cumulatives provide a closure test of leading-power endpoint factorization and are sensitive to direct- $O_{7}$ power corrections and resolved-photon effects. The BTEC thereby adds information on the angular structure of the inclusive recoil jet beyond the ordinary photon spectrum and may improve signal--background discrimination when their energy-flow profiles differ.
hep-phhep-ex0 citations
09
Photon-calibrated event-activity bias and subcollision geometry in d+Au collisions at $s_{N N}$ = 200 GeV with PYTHIA 8 Angantyr
Muhammad Ajaz🇸🇦 · Haifa I. Alrebdi🇸🇦 · Muhammad Waqas🇨🇳
Event-activity selections in small nuclear collision systems couple collision geometry to the soft response accompanying a hard scattering. We examine this coupling in d+Au collisions at $s_{N N}$ = 200 GeV with PYTHIA 8.316 Angantyr, using direct photons, terminal pre-decay neutral pions, and anti-kT jets. A hard-bias factor compares the probability for a hard event to enter an activity class with an $N_{co l l}^{N D}$ -weighted minimum-bias reference. The model predicts a depleted most-active class and an enhanced peripheral class for both photons and pions. Photon-tagged events also sample a smaller mean impact parameter and more nondiffractive subcollisions than pion-tagged or inclusive HardQCD events. Comparing fully correlated Angantyr events with an Ncoll-reweighted minimum-bias reference and a factorized diagnostic separates the explicit geometric contribution from residual hard-soft correlations. STAR-like and PHENIX-like particle-level activity proxies preserve the class ordering but give different class probabilities. The calculation is generator-level and does not identify a unique microscopic origin for the residual correlations.
hep-phnucl-exnucl-th0 citations
10
Unbiased Data-Driven Determination of the Nuclear Dipole Amplitude in the Color Glass Condensate
Si-Wei Dai🇨🇳 · Haowu Duan🇨🇳 · Long-Gang Pang🇨🇳 · Guang-You Qin🇨🇳 · Shu-Yi Wei🇨🇳 · Han-Zhong Zhang🇨🇳 · Wenbin Zhao🇨🇳
Gluon saturation limits the growth of parton densities at small Bjorken- $x$ and is expected to be most pronounced in heavy nuclei. Yet quantitative extractions of the nuclear gluon dipole amplitude have long relied on parametrized initial conditions, introducing uncontrolled model dependence that obscures genuine nuclear effects. We introduce a physics-informed neural-network framework that embeds the collinearly improved Balitsky-Kovchegov evolution equation directly into the training objective, allowing the impact-parameter-averaged dipole amplitude to be determined from data without assuming a functional form for its initial condition. Applying this framework to forward-hadron nuclear-modification-factor and coherent $J / ψ$ photoproduction data, we extract the $^{208}$ Pb dipole amplitude at $x_{0} = 0.01$ with QCD evolution and momentum-space positivity enforced throughout training. The evolved amplitude reproduces the measured cross sections across the available kinematic range and yields a saturation-scale ratio $Q_{s 0, Pb}^{2} / Q_{s 0, p}^{2} = 3.1 7_{- 0.10}^{+ 0.17}$ , consistent with simple geometric scaling. The extracted Pb initial condition is well described by a McLerran-Venugopalan-type form, in contrast to the proton, reflecting the higher color-charge density of a large nucleus. Using the same amplitude, we predict the rapidity dependence of the transverse-momentum ratio in $pp$ , $p$ Pb, and Pb $p$ collisions, finding agreement with recent LHCb measurements at low multiplicity without any system-dependent parameters. This work provides the first unbiased, data-driven determination of nuclear structure in the saturation regime and establishes a general strategy for embedding nonlinear evolution equations into machine-learning extractions of dynamically constrained observables.
hep-phnucl-exnucl-th3 citations
11
Magnetic dipole moments as probes of doubly-bottom molecular pentaquarks
Ulaş Özdem🇹🇷
We investigate the magnetic dipole moments of doubly-bottom pentaquark states with spin-parities $J^{P} = \frac{1}{2}^{-}$ and $\frac{3}{2}^{-}$ , interpreted as hadronic molecules in the $B Σ_{b}$ , $B Σ_{b}^{*}$ , and $B^{*} Σ_{b}$ configurations. The analysis is performed within the framework of QCD light-cone sum rules employing photon distribution amplitudes. Our results demonstrate a strong sensitivity of the magnetic dipole moments to the internal spin structure and quark composition of the states. In particular, the light-quark sector provides the dominant contribution in the $B Σ_{b}$ configuration, while the magnetic moment of $B Σ_{b}^{*}$ is largely governed by the heavy bottom quark. For the $B^{*} Σ_{b}$ molecular state, both light and heavy sectors contribute constructively, leading to a significantly enhanced magnetic dipole moment. These findings indicate that magnetic dipole moments constitute a sensitive probe of the internal structure of molecular-type doubly-bottom pentaquarks and provide testable predictions for future experimental studies.
hep-phhep-exhep-lathep-th0 citations
12
Laplace-Space Analysis of $x F_{3}$ Including Nuclear Effects and Gegenbauer-Polynomial Parton Distributions
Shahin Atashbar Tehrani🇮🇷 · Javad Sheibani🇮🇷 · Elham Astaraki🇮🇷
We present a next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) QCD analysis of the non-singlet structure function $x F_{3}$ , utilizing a Gegenbauer-polynomial representation for the input parton distribution functions (PDFs). The main objective is to assess how this flexible parameterization improves the extraction of valence quark distributions in the presence of nuclear effects. To this end, we incorporate nuclear modification factors into the input PDFs for heavy nuclear targets and solve the DGLAP evolution equations analytically in Laplace space. The structure function in Bjorken- $x$ space is then reconstructed using a Jacobi polynomial expansion. This combined framework enables a systematic investigation of the $x F_{3}$ data from the CCFR, NuTeV, and CHORUS experiments at both NLO and NNLO accuracies. We further examine the sensitivity of the extracted distributions to nuclear corrections and discuss their implications for the Gross--Llewellyn Smith, Bjorken, and Adler sum rules. Our results demonstrate that the Gegenbauer-polynomial PDF formalism provides a flexible and efficient framework for describing nuclear $x F_{3}$ data, yielding improved phenomenological consistency across a wide kinematic range.
hep-ph0 citations
13
Roles of $a_{0} (980)^{+} f_{0} (500, 980)$ and $a_{1} (1260)^{+} η$ production mechanisms in decay $D_{s}^{+} \to π^{+} π^{0} π^{0} η$
Jun He🇨🇳
In this work, we theoretically investigate the decay mechanism of $D_{s}^{+} \to π^{+} π^{0} π^{0} η$ based on BESIII data, considering two mechanisms: the production of two dynamically generated resonances, $D_{s}^{+} \to a_{0} (980)^{+} f_{0} (500, 980)$ , and a process with one dynamically generated resonance, $D_{s}^{+} \to a_{1} (1260)^{+} η$ . In the first mechanism, the interactions $π^{+} η$ and $K^{+} K ˉ^{0}$ are included to generate the $a_{0} (980)^{+}$ , while coupled-channel interactions involving $π^{+} π^{-}$ , $π^{0} π^{0}$ , $K^{+} K^{-}$ , $K^{0} K ˉ^{0}$ , $η η$ , and $π^{0} η$ are adopted to generate the $f_{0} (500)$ as well as the $f_{0} (980)$ . For the second mechanism, the $π ρ$ and $K ˉ^{*} K - K^{*} K ˉ$ channels are included to generate the $a_{1} (1260)$ . With these interactions, the amplitudes are calculated in the chiral unitary approach and used to compute the invariant mass spectra of $D_{s}^{+} \to π^{+} π^{0} π^{0} η$ . The results suggest that the peak near 1000~\text{MeV} in the $π^{+} η$ invariant mass spectrum can be well interpreted as the $a_{0} (980)^{+}$ arising from a cusp effect. The $f_{0} (980)$ , generated together with the $f_{0} (500)$ , is responsible for the small structure near 1000 MeV in the $π^{0} π^{0}$ spectrum. The $a_{1} (1260)^{+}$ and its decay to $ρ^{+} π^{0}$ followed by the subsequent $ρ^{+}$ decay provide a good description of the $π^{+} π^{0} π^{0}$ and $π^{+} π^{0}$ mass spectra. The inclusion of an additional resonance near 800 MeV in the $π^{+} η$ spectrum leads to only a marginal improvement of the fit.
hep-ph0 citations
14
Charge-exchange reactions with pion and kaon beams in the NA64h experiment at CERN
Sergei N. Gninenko🇷🇺 · Sergey Kuleshov🇨🇱 · Valery E. Lyubovitskij🇨🇱 · Alexey S. Zhevlakov🇷🇺
We discuss a new approach to search for dark sector coupled to quarks in the invisible decays and oscillations of light neutral mesons produced in the charge-exchange (CEX) reactions with pion and kaon beams $π^{-} (K^{-}) + (A, Z) \to π^{0}, η, η^{'} (K ˉ^{0}) + (A, Z - 1)$ at nuclei target $(A, Z)$ in the NA64h experiment at CERN for $P_{Lab}$ running in the interval from 5 to 50 GeV. For estimating of the projection sensitivity for the proposed searches the knowledge of the meson yield is crucial. This work is dedicated to the accurate evaluation of CEX cross sections for the wide range of energies and target nuclei which could be also useful for other experiments.
hep-ph0 citations
15
Systematic derivation of the Boltzmann equation for electroweak baryogenesis
Motoi Endo🇯🇵 · Yushi Mura🇯🇵 · Tenta Tsuji🇯🇵
We derive the Boltzmann equation for electroweak baryogenesis within a field-theoretical framework. We first algebraically solve the Kadanoff--Baym equations by incorporating the effects of gradients of the CP-violating bubble-wall background order by order. We then apply approximations and assumptions appropriate for electroweak baryogenesis and identify the on-shell parts of the solutions, which describe quasiparticle states propagating in a plasma. Using these on-shell solutions, we derive the Boltzmann equations for flavor-diagonal quasiparticle modes, while neglecting the off-diagonal components describing quantum coherence between different flavor modes. Our derivation generalizes previous field-theoretical treatments by retaining self-energy corrections, and our results are consistent with the known Boltzmann equations when these corrections are neglected. This framework provides a systematic and transparent derivation applicable to multi-flavor bosonic and fermionic systems.
hep-phastro-ph.COhep-th0 citations
16
Collider Spin Tomography with Missing Neutrinos
Tengyu Ai🇨🇳 · Qi Bi🇨🇳 · Yuxin He🇨🇳 · Zekun Li🇨🇳 · Jia Liu🇨🇳 · Xiao-Ping Wang🇨🇳
Missing neutrinos need not destroy collider spin tomography. We formulate the visible measurement under kinematic ambiguities arising from invisible particles as a coarse-grained positive-operator-valued measure on the production spin density matrix. We show that information loss is governed by the null space of the resulting visible-data map, not by the number of kinematic solutions. In $e^{+} e^{-} \to τ^{+} τ^{-} \to π^{+} π^{-} + ν ν ˉ$ , the twofold ambiguity leaves only the antisymmetric spin-correlation combination $C_{n r} - C_{r n}$ unidentifiable, while the differential production rate and the remaining fourteen spin coefficients are identifiable. For practical reconstruction under kinematic ambiguities, we develop a self-consistent fixed-point unfolding method using only visible data, without assuming a theoretical production template. Closure tests in Standard Model and anomalous tau-dipole benchmarks show that the method reproduces the truth-level differential production rate and all identifiable spin coefficients, whereas the usual flat average over kinematic folds gives significantly biased reconstructions. When a nontrivial null space is present, the reconstructed identifiable subspace together with positivity yields controlled ranges for concurrence and the CHSH parameter.
hep-phhep-exquant-ph0 citations
17
Dynamical flattening of halo density cusps by Q-ball dark matter
Alexander Libanov🇷🇺 · Sergey Troitsky🇷🇺
Cold, collisionless dark matter successfully explains a wide range of observations, including the formation of large-scale structure. Nevertheless, tensions remain on small, galactic scales, most notably the cusp-core, or inner-mass-deficit, problem and the diversity of inner rotation-curve shapes and central densities at fixed halo mass. These observations suggest that additional dark-sector physics may affect the inner structure of halos, although no generally accepted explanation has yet emerged. Here, making use of a toy but representative model, we show that interacting dark-matter Q-balls -- non-topological solitons stabilized by a conserved charge -- can provide a natural mechanism for halo cusp flattening and may contribute to observed diversity of inner halo profiles. Produced in the early Universe in the dark sector, these Q-balls grow in the dense central regions of halos, while their interaction cross section decreases as the soliton mass increases. This process operates preferentially in halo centers, converting part of the rest-mass energy stored in massive Q-balls into relativistic dark-sector particles and thereby modifying the inner mass-density profile. The resulting density-dependent, self-regulating energy loss provides a dynamical mechanism for flattening halo cusps while leaving the outer halo largely unaffected.
hep-phastro-ph.COastro-ph.GA0 citations
18
Three Texture Zeros in the Hermitian Dirac sector within Type-I Seesaw Mechanism
Richard H. Benavides🇨🇴 · John D. Gómez🇨🇴 · William A. Ponce🇨🇴
We present numerical benchmark solutions for Hermitian Dirac neutrino mass matrices with three texture zeros within the type-I seesaw mechanism. The analysis is to normal ordering (NO) and inverted (IO). The heavy Majorana mass matrix is assumed diagonal, while the Dirac mass matrix is taken Hermitian. Four viable textures in NO are shown to reproduce the neutrino oscillation observables within the $3 σ$ ranges of the NuFIT global analysis, and three viable textures in IO.
hep-ph0 citations
19
LISA Reconstruction Landscape for Metastable Cosmic Strings
Satyabrata Datta🇨🇳 · Rome Samanta🇮🇹
We study reconstruction of stochastic gravitational-wave backgrounds from metastable cosmic strings with the Laser Interferometer Space Antenna (LISA). In the vacuum-tunneling benchmark, the network decays via zero-temperature nucleation of monopole pairs on the string worldsheet. Initially following cosmic-string scaling, loop production is suppressed after a decay time linked to efficient loop breaking and network collapse. This finite lifetime imprints an infrared tail and a transition toward a stable-string-like high-frequency plateau. Using synthetic LISA data with instrumental noise and unresolved astrophysical foregrounds, we perform Bayesian analysis in the $(G μ, κ_{CS})$ parameter space. We map detectability, uncertainties, correlations, and localization to distinguish background detection from parameter reconstruction. Reconstruction is governed by lifetime-dependent spectral features in the LISA band. When LISA samples the transition between tail and plateau, data contain amplitude and shape information, enabling recovery of string tension and metastability scale. Posteriors may remain correlated, reflecting an amplitude--lifetime trade-off, yet occupy a small parameter region. By contrast, featureless spectra constrain only limited parameter combinations or become prior dominated. High-SNR plateau-like spectra can retain partial sensitivity to $κ_{CS}$ through residual lifetime dependence even when the transition is not prominent. Finally, we assess sensitivity to Galactic foreground modeling by comparing a flexible template with a reduced tanh template. Our results show where LISA can move beyond detection to probe the lifetime of the underlying string network.
hep-phastro-ph.COgr-qc1 citation
20
Why 4D? Spontaneous Dimensional Selection from Gauge Criticality
Wen Yin🇯🇵
Noting that the Yang--Mills coupling is relevant below four dimensions, marginal in four dimensions, and irrelevant above four dimensions, I propose that this criticality can lead to the selection of four macroscopic dimensions. As a proof of principle, I present a concrete racetrack model of the type commonly studied in extra-dimensional scenarios, but without assuming a noncompact 4D spacetime. I find, within a well-controlled model without specifying the 4D, that 4D spacetime is spontaneously realized through radion stabilization via gauge-criticality-induced supersymmetry breaking and supergravity effects.
hep-phhep-th0 citations
21
Improved Approximations for Collective Neutrino Oscillations
Matthew Riccio🇺🇸 · A.B. Balantekin🇺🇸
A one- and two-body $su (n)$ Hamiltonian governing the dynamics of many systems, including collective neutrino oscillations, is investigated. We start by analyzing the algebraic structure( $u (n^{N})$ ), formulate a product structure of the algebra, and utilize this to construct generic expressions for operator expectation values, Rényi Entropy, and Wigner Functions. Performing BBGKY hierarchy truncation we develop a systematic methodology for going beyond the mean field with polynomial scaling on a classical computer.
hep-ph0 citations
22
A Periodically Interacting Dark Sector: Signatures and Constraints from CMB and Cosmic Expansion Data
Marco Antonio Cardoso Alvarez🇧🇷 · Micol Benetti🇮🇹 · Leila Graef🇧🇷 · Robert Brandenberger🇨🇦
We introduce a novel cosmological model that provides an effective description of the back-reaction of super-Hubble fluctuations on the cosmological background, a generic effect expected to arise in any cosmological scenario without requiring additional ingredients. At the phenomenological level, it can be interpreted as an interacting dark sector scenario in which the sign of the energy transfer changes periodically over time. We constrain the model using CMB, BAO, and Type Ia supernova data. We find that a significant amplitude of the oscillatory interaction is allowed by the data, although there is no statistically significant preference for this model over $Λ$ CDM.
↳ astro-ph.COgr-qchep-phhep-th0 citations
23
Non-linear Evolution of Dark Plasma Subhalos
Andrew Liu🇺🇸 · Anirudh Prabhu🇺🇸 · Akaxia Cruz🇺🇸 · Mariangela Lisanti🇺🇸
Dark matter that self interacts through long-range forces exhibits coherent, collective effects that are absent in short-range interactions. In the case where dark matter interacts through a hidden-photon mediator, its dynamics closely resemble those of Standard Model plasmas. In such models, various astrophysical environments, including cluster collisions and subhalos orbiting their host halo, are susceptible to plasma instabilities: processes that modify the dark matter velocity distribution and lead to exponential growth of dark electromagnetic fields. In this paper, we present the first study of the non-linear evolution of electrostatic instabilities in dark matter subhalos orbiting within the Milky Way potential using a suite of particle-in-cell simulations. We find that the growth and saturation of these instabilities produce substantial turbulent heating and mass loss, with an efficiency that depends sensitively on subhalo mass and orbital eccentricity. For highly eccentric orbits, plasma heating can reduce the initial mass of a $1 0^{7}$ ( $1 0^{9}$ ) $M_{⊙}$ subhalo by as much as $\sim 97%$ ( $\sim 84%$ ) soon after first pericenter. Plasma-induced heating and stripping may therefore leave observable signatures in the Milky Way subhalo population, including a suppression of the low-mass subhalo mass function.
↳ astro-ph.COhep-phphysics.plasm-ph0 citations
24
Semi-analytic Inference of Satellite Densities in the Cold Dark Matter Model Part I. Comparison to Ultra-faint Dwarf Kinematics
Kailash Raman🇺🇸 · Dylan Folsom🇺🇸 · Manoj Kaplinghat🇺🇸 · Mariangela Lisanti🇺🇸 · Benjamin R. Safdi🇺🇸
Ultra-faint dwarf galaxies are critical testing grounds for probing the limits of galaxy formation in the cold dark matter (CDM) paradigm. Employing a semi-analytic cosmological satellite generator that captures the expected CDM halo population, we estimate Milky Way dwarf density profiles through two methods: a kinematic approach using stellar velocity dispersions and a separate method based on dwarf stellar masses. The kinematic approach yields a larger diversity in central dark matter densities than expected from the CDM population, as inferred from the stellar-to-halo mass relation, with compact ultra-faints appearing overdense and larger systems appearing underdense. For the ultra-faint dwarfs with at least 10 stars with spectroscopic measurements, this discrepancy persists at the ~2.4 $σ$ level across all considered systematic variations on the semi-analytic modeling. Our framework introduces a novel, robust procedure for testing the consistency of the observed population of Milky Way satellites with cosmological expectations. As future surveys discover new dwarf satellites and refine stellar velocity measurements, updating this analysis will provide an increasingly stringent test of the CDM paradigm.
↳ astro-ph.GAastro-ph.COhep-ph0 citations
25
Wading the String Bog: CMB Birefringence in the Swampland
Guido D'Amico🇮🇹 · Nemanja Kaloper🇺🇸 · Alexander Westphal🇩🇪
We point out that observations of cosmic birefringence may provide direct experimental tests of Swampland conjectures. Ultralight scalar field birefringence mechanisms are constrained by Weak Gravity Conjecture, limiting their parameter space. Conversely, confirming that CMB birefringence is caused by ultralight scalars could spell problems for the Swampland framework. Resolving these difficulties without a revision of Swampland ideology points toward thin axionic domain walls, which can explain birefringence without propagating ultralight degrees of freedom. Importantly these conflicting scenarios for cosmic birefringence could be experimentally distinguished by a search for, or exclusion of, birefringence anisotropies, that could be measured by POLARBEAR, Simons Observatory and LiteBIRD. We also note that cosmic birefringence observables emerge via a Sakharov-like asymmetry, where linear polarization is first generated cosmologically and subsequently twisted by a parity-violating dynamics after last scattering.
↳ hep-thastro-ph.COgr-qchep-ph0 citations
26
geoSCET: Soft Theorems from Power Counting
Timothy Cohen🇨🇭 · Patrick Hager🇨🇭 · Andreas Helset🇨🇭
We apply the framework of Soft Collinear Effective Theory (SCET) to the theory of the geometric scalar field. The resulting ``geoSCET'' manifests an emergent geometry in the soft sector, mirroring the emergent soft gauge invariance of QCD SCET. We use geoSCET to derive the geometric soft theorems as straightforward consequences of effective-field-theory power counting, including extensions to multiple soft emissions and loop corrections. We demonstrate that theories without a potential satisfy universal geometric soft theorems for any number of soft emissions to all orders in perturbation theory. We also show that we can turn on a potential at the soft scale without spoiling the factorization of the soft physics. This work demonstrates the underlying field-space diffeomorphism origin of the geometric soft theorem.
↳ hep-thhep-ph1 citation
27
Semi-analytic Inference of Satellite Densities in the Cold Dark Matter Model Part II. Implications for Dark Matter Indirect Detection Constraints
Kailash Raman🇺🇸 · Dylan Folsom🇺🇸 · Manoj Kaplinghat🇺🇸 · Mariangela Lisanti🇺🇸 · Benjamin R. Safdi🇺🇸
Dwarf galaxies provide excellent targets to search for signals of dark matter annihilation or decay. Using a calibrated semi-analytic model and the latest stellar kinematic data (presented in Part I), this paper updates the astrophysical J-factors for the Milky Way's dwarf spheroidal galaxies. We infer the probability distributions for the J-factors of 39 dwarfs by conditioning a population of subhalos, generated with the SatGen semi-analytic satellite model, on either a dwarf's kinematically determined dynamical mass or its stellar mass. We also compute the J-factors using the Jeans equation with updated stellar kinematics and priors that incorporate varying degrees of SatGen information. We use the computed J-factors to recast existing limits from Fermi-LAT data on the annihilation cross section. Our main result is that variations in the J-factors computed using the Jeans analysis introduce a factor of 2-4 uncertainty into the inferred limits on the cross section. We argue that a cosmologically informed prior is a motivated choice that excludes thermal relic annihilation cross sections to $b b ˉ$ below about 70 GeV. For comparison, the more commonly used priors, which can lead to unphysical halo parameters, exclude masses below 130 GeV at 95% confidence level. We also show that the highest-J-factor dwarfs are spatially extended, approximately one degree on the sky, which challenges the validity of the point-source approximation adopted in many analyses of Fermi data. Finally, based on the semi-analytic model and the kinematic data, the highest J-factor halos have already been discovered, suggesting future ultra-faint discoveries are unlikely to substantially strengthen limits on annihilating dark matter.
↳ astro-ph.HEastro-ph.COhep-ph0 citations
28
Gravitational Waves as a Source of Large-Scale White Noise: New Constraints
Gabriela Barenboim🇪🇸 · Albert Stebbins🇺🇸
A stochastic gravitational wave (GW) background sources a shear in the flow of cosmic fluid which, through non-linear mode coupling, generates large-scale white noise (LSWN) in the kurvature density field. Building on the LSWN framework of our previous work, we derive the amplitude of this GW-induced LSWN and translate the observational non-detection of LSWN into bounds on the production redshift and density of gravity waves. In particular, a minimal constraint on gravity waves with $z = 0$ density parameter $Ω_{GW0}^{*}$ in frequency band $f_{*}$ generated at redshift $z_{*}$ must satisfy $z_{*}^{2} Ω_{GW0}^{*} < 5 \times 1 0^{7} (f_{*} / nHz)^{3/2}$ . This, for example, precludes the gravity waves recently detected by pulsar timing arrays \cite{NANOGrav:2023hvm} from being present before $z_{*} \sim 1 0^{8}$ , long after the quark hadron phase transition. While orders of magnitude stronger than other constraints on gravity waves, this is a minimal LSWN constraint as realistic modeling of early universe gravity wave production, including the granularity of the gravity-wave sources and the LSWN produced by the associated acoustic waves would probably tighten this constraint by orders of magnitude.
↳ astro-ph.COgr-qchep-ph1 citation
29
Spectator Axions in String Inflation and Primordial Black Holes
Michele Cicoli🇮🇹 · Dario L. Lorenzoni🇨🇦 · Evan McDonough🇨🇦 · Francisco G. Pedro🇮🇹
We study the impact of light spectator axions on the seeding of primordial black holes (PBHs) during inflation in string theory. Primordial black holes exhibit unique and novel phenomenology, and may constitute the observed dark matter. Cosmic inflation provides a mechanism for producing them, but such inflation models typically feature Planckian field excursions, necessitating an ultraviolet completion into quantum gravity. String theory provides a natural framework for doing so, and indeed Fibre Inflation has been shown to produce PBHs while satisfying constraints from cosmic microwave background data. In this work we study the dynamics of axions during Fibre Inflation, and find a diverse and rich set of possibilities, including turns in field space and enhancement of primordial perturbations. We find that across most of parameter space, notably an axion with a far sub-Planckian decay constant $f ≪ M_{Pl}$ , there is a negligible impact on the power spectrum of curvature perturbations, indicating an overall robustness of the model. On the other hand, an axion with a larger but still sub-Planckian decay constant, $f ≳ O (0.1) M_{Pl}$ , and an exponentially small prefactor of its non-perturbative potential, can enhance the growth of perturbations, making it easier to achieve the amplification needed to seed PBHs, effectively realizing axion-assisted PBHs in string theory.
↳ hep-thastro-ph.COgr-qchep-ph0 citations
30
$w_{1 + \infty}$ as the Frame Algebra of Kerr Soft Dressing
Gabriel Menezes🇧🇷
The Veneziano--Vilkovisky supertranslation is the residual large diffeomorphism relating the canonical Bondi frame to the intrinsic frame of the scattering bodies. We show it leads a tower selected by the exponentiating soft expansion, the object generating the Kerr multipoles at three points. Since $e^{\eta\omega a\cdot q}$ splits into even and odd parts, the tower alternates parity, and for aligned spin we solve it to all orders in hyperbolic integrals. After a chiral projection its composition law is the classical $w_{1 + \infty}$ bracket: the physical content we assign to that algebra.
↳ hep-thgr-qchep-ph1 citation
31
Kerr Soft Dressing and the $w_{1 + \infty}$ Frame Algebra at Null Infinity
Gabriel Menezes🇧🇷
We construct the charge-generated intrinsic/canonical frame dictionary associated with the Kerr-selected soft dressing. Starting from the VV supertranslation, we formulate the higher-spin problem as an inverse problem at null infinity: the soft kernel $K_{A B}^{(s, 0)} [t]$ , built from the parity-adapted maximally longitudinal scalar $χ_{t}^{(s)}$ , is matched to the Kerr-selected exponentiating projection of the universal soft contribution, thereby determining one parity component of the generator $t^{A_{1} \dots A_{s}}$ . Helicity conjugation fixes which one: the exponentiating source obeys $S_{+, exp}^{(s)} = (- 1)^{s} S_{-, exp}^{(s)}$ , so the tower fixes the electric projection of the source at even levels and the magnetic projection at odd ones, matching the alternation of the Kerr mass and current moments; for aligned spin the projection is exhaustive and we solve the tower in closed form. The prescription reproduces the VV supertranslation at leading order and fixes the curl, not the divergence, of a smooth generalized-BMS vector at subleading order. The reason for the matching is physical: the same exponentiating soft factor is the classical limit of the Guevara--Ochirov--Vines spinning three-point operator and generates the Kerr multipole tower. We explain the corresponding hard flux charges and show how their external-state action gives the Ward representation of the soft theorem. The polynomial Poisson algebra on $T^{*} S^{2}$ , with local $w_{1 + \infty}$ -type reductions, then acts on these frame-changing generators; it does not close on the Kerr-selected data alone. This gives the physical role of the $w_{1 + \infty}$ -like structure in Kerr black-hole scattering: it moves the intrinsic/canonical dictionary. Its observable imprint begins with displacement memory at $s = 0$ and spin memory at $s = 1$ , followed by higher electric and magnetic memory moments.
↳ hep-thgr-qchep-ph2 citations
32
A Lightweight Foundation Model for Collider Physics with Multi-Domain Adaptation
Liangyu Wu🇺🇸 · Qibin Liu🇺🇸 · Alexander Yue🇺🇸 · Julia Gonski🇺🇸
We present a lightweight approach to foundation modeling (\textbf{NEXUS}) that leverages pre-trained learning from collider physics data towards out-of-domain tasks in other scientific datasets, using a fully connected autoencoder model with approximately 3 million parameters. The model pre-trains with no supervision over a large-scale collision dataset from the Large Hadron Collider modeled by charged particle track features. Downstream tasks for collider analyses, such as kinematic regression and event classification, are developed on pre-trained model weights and achieve improved accuracy with only small labeled datasets when compared to equivalent architectures trained from scratch. The benefits of pre-training are additionally investigated through latent space interpretation and application to other domains, including gravitational waves, flood forecasting, and neural activity. Furthermore, the relative computational simplicity of NEXUS is demonstrated compared to transformer approaches at comparable scale, opening the door to power-efficient inference and real-time or edge applications of foundation models in scientific experiments.
↳ cs.LGhep-ph0 citations
33
CLVisc Agent for autonomous relativistic hydrodynamics studies
Qi Wang🇨🇳 · Long-Gang Pang🇨🇳 · Shi Pu🇨🇳 · Xin-Nian Wang🇨🇳
We enable large language model (LLM) agents to autonomously perform end-to-end hydrodynamic simulations of the quark-gluon plasma evolution and calculation of final hadron spectra in relativistic heavy-ion collisions. We design a meta skill that allows an agent to explore a project's source code, craft a specialized skill, and iteratively refine it. Applying this meta skill to the (3+1)D viscous hydrodynamic code CLVisc, the agent builds a CLVisc skill encoding its operational knowledge and then independently executes full scientific workflows: designing parameter scans, running simulations, comparing ensemble results, and producing publication-ready figures. Crucially, the agent draws on literature-informed heavy-ion physics to select physically meaningful observables and interpret outcomes without explicit instruction. We demonstrate the pipeline in two scenarios: temperature-dependent shear viscosity over entropy density $η / s$ , and nuclear-structure effects in O+O collisions at $s_{NN} = 5.36$ ~TeV using four \textit{ab initio} descriptions of $^{16}$ O. In both, the agent plans, executes, and analyzes autonomously, devising new initial-state observables to explain final observations and extract qualitative knowledge. The meta skill is agnostic to code versions and Monte Carlo generators, promising future multi-agent systems in high-energy nuclear physics.
↳ nucl-thhep-ph1 citation
34
Thermal Breaking of the I-Love Universality for Hot White Dwarfs
Jinyi Lv🇨🇳 · Jing-Yi Wu🇨🇳 · Hongji Chen🇨🇳 · Kexin Jia🇨🇳 · Weihan Sun🇨🇳 · Kilar Zhang🇨🇳
The universal I-Love-Q relations for compact stars have significant applications in gravitational-wave astronomy, but thermal effects can break these relations in low-mass white dwarfs. In this work, we employ the stellar evolution code MESA to construct realistic models of $0.15 M_{⊙}$ helium-core and $0.6 M_{⊙}$ carbon-oxygen core white dwarfs at various temperatures. By utilizing the Clairaut-Radau equation, we quantitatively extract the radial variation of the eccentricity of internal isodensity surfaces. Our numerical results demonstrate that higher central temperatures amplify the eccentricity variation, causing the I-Love relations to deviate from the zero-temperature Chandrasekhar model, whereas subsequent cooling restores them. This confirms that the temperature-induced violation of the universal relations is fundamentally driven by the loss of self-similarity in isodensity surfaces, providing key insights into the applicability conditions of I-Love-Q relations in compact objects.
↳ astro-ph.HEgr-qchep-phhep-th0 citations
35
Non-conformal obstructions to bubble expansion
David Mateos🇪🇸 · Mikel Sanchez-Garitaonandia🇮🇪 · Pedro Tarancón-Álvarez🇪🇸
We investigate the hydrodynamics of expanding bubbles in first-order phase transitions with non-conformal thermodynamics. We analyze a broad class of equations of state interpolating between bag-model descriptions, commonly used for electroweak transitions, and QCD-like theories. As a concrete benchmark, we determine the bubble solutions for pure SU(3) Yang-Mills theory. We uncover a new set of hydrodynamic obstructions to bubble expansion. These obstructions arise both at the bubble wall and along the fluid flow, and can partially or completely eliminate otherwise allowed solutions. We also identify a new class of solutions, which we dub "shocked detonations", consisting of ordinary detonations with an additional shock inserted in the rarefaction wave. As a consequence of these obstructions, the space of admissible bubble wall velocities is significantly constrained, with gaps appearing between different expansion regimes. For example, for QCD-like theories, all detonation solutions, including shocked detonations, are excluded. We show that these effects can strongly impact the kinetic energy budget of the fluid and, therefore, the resulting gravitational-wave signal, potentially suppressing the most efficient configurations. Our results highlight the importance of non-conformal dynamics for accurately modeling phase transitions and the resulting gravitational-wave spectrum. The code used to construct the bubble solutions is publicly available. For completeness, we also show how the interpolation between the bag-model and QCD-like limits can be realized holographically by varying the backreaction of matter fields on the geometry.
↳ hep-thastro-ph.HEgr-qchep-ph0 citations
36
A regulated zero-temperature construction of the Fundamental Modular Region in pure Yang--Mills theory and QCD
Rodrigo Carmo Terin🇪🇸
We formulate the Fundamental Modular Region (FMR) as the zero-temperature limit of regulated copy-weighted Landau gauges. At finite $β$ , the measure localizes on absolute minima, and the leading correction is dominated by the inverse Faddeev--Popov (FP) operator. A small $S U (2)$ benchmark provides a computational realization through population annealing and collective basin hopping. Our construction defines absolute Landau gauge without parametrizing the FMR boundary and extends naturally to full quantum chromodynamics (QCD). It also admits a Hamiltonian interpretation in terms of the gauge-fixed vacuum wave functional on the FMR.
↳ hep-thhep-lathep-phnucl-th0 citations
37
Comparative Periodogram Analysis of 22 Years of Super-Kamiokande Solar $^{8} B$ Neutrino Data: Classical, Phase-Based, and Information Theoretic Methods
Liangliang Ren🇨🇳 · Ze-Lin Zhang🇨🇳 · Bing Xu🇨🇳 · Tian-Cheng Huang🇨🇳 · Ran Wang🇨🇳 · Jia-Xin Dong🇨🇳 · Yan-Ping Wang🇨🇳
Solar $^{8} B$ neutrinos offer a unique probe of solar interior dynamics and neutrino electromagnetic properties. We present a systematic, multi-method periodogram analysis of the 22-year Super-Kamiokande solar neutrino dataset (1996--2018), comparing nine algorithms. Through hierarchical temporal segmentation, we disentangle astrophysical signals from detector systematics. The Generalized Lomb-Scargle (GLS) method provides the most statistically robust detections by correctly handling heteroscedastic uncertainties, whereas classical Lomb-Scargle systematically underestimates significance. The Lafler--Kinman method generally fails, whereas independent algorithms like MHAOV and PDM1 recover consistent periodicities, providing vital cross-validation. In pre-2001 and SK-I data, seven algorithms provide \textit{weak evidence} ( $ln B > 0$ ) for a $\sim 38.8$ d periodicity. However, this signal is entirely absent in the highest-statistics SK-IV modified flux data, where the Bayes factor decisively favors the null model ( $ln B ≪ - 5$ ), indicating it is a transient feature of the early low-statistics era. Conversely, a $\sim 24.3$ d signal in post-2001 raw flux is decisively rejected by the Bayesian framework and vanishes in modified flux, confirming its seasonal systematic origin. Furthermore, no evidence is found for an $\sim 11$ -year solar cycle modulation, yielding a stringent amplitude upper limit of $< 0.2%$ of the mean flux. By highlighting the stark contrast between frequentist significance and Bayesian model selection ( $ln B$ ) in low signal-to-noise regimes, we establish a rigorous, multi-metric best-practice framework for periodicity searches. This work provides a direct methodological blueprint for next-generation observatories like Hyper-Kamiokande and JUNO.
↳ astro-ph.HEhep-ph0 citations
38
Probing (Hyper)Nuclei Wave Functions and Production Mechanisms in $s_{NN} = 200$ GeV Isobar Collisions at RHIC
STAR Collaboration
The study of nuclei and hypernuclei production is a powerful tool to investigate the formation mechanism of loosely bound states in high-energy heavy-ion collisions. A key prediction from coalescence models is a strong suppression of the hypertriton ( $_{Λ}^{3} H$ ) compared to $^{3} He$ production in small collision systems due to the larger radius of $_{Λ}^{3} H$ . In this letter, the STAR collaboration reports measurements on (hyper)nuclei ( $_{Λ}^{3} H,_{Λ ˉ}^{3} H ˉ,^{3} He,^{3} He, t$ ) production at mid-rapidity in Ru+Ru and Zr+Zr collisions at $s_{NN} = 200$ GeV as a function of collision centrality. We find that the ratios $N_{t} N_{p} / N_{d}^{2}$ and $S_{3} = (N_{_{Λ}^{3} H} / N_{_{3} He}) / (N_{Λ} / N_{p})$ deviate significantly from thermal model expectations. Coalescence calculations incorporating realistic non-Gaussian wave functions for the $d$ and $_{Λ}^{3} H$ provide an improved description of the data, while Gaussian descriptions of the $_{Λ}^{3} H$ wave function fail to simultaneously reproduce the measured $S_{3}$ and the binding energy of $_{Λ}^{3} H$ . These results suggest that the $_{Λ}^{3} H$ wave function contains larger short-distance $d$ -- $Λ$ probability than implied by a Gaussian ansatz, demonstrating the potential of heavy-ion production measurements as a probe of hypernuclear wave functions and the underlying hyperon--nucleon interaction.
↳ nucl-exhep-exhep-phnucl-th1 citation
39
Domain walls through different cosmologies
I. Dankovsky🇷🇺 · D. Gorbunov🇷🇺 · S. Ramazanov🇷🇺 · A. Vikman🇨🇿
We study properties of domain walls (DWs) arising in the model with a double well potential assuming different early universe cosmologies: from dust through stiff matter domination to the limit of effective Minkowski space. Using lattice simulations we demonstrate that evolution of DW networks exhibits an approximate universality with respect to the cosmological equation of state (EoS). Namely, the wall area inside a given large volume is mainly determined by the particle horizon, while details of cosmic expansion play a subdominant role. As it follows, particle horizon rather than the inverse Hubble rate is pivotal in DW evolution defining the network correlation length and hence its phenomenology, e.g., the characteristic wavelength of emitted gravitational waves (GWs). Formation of closed DWs is shown to be very sensitive to the cosmological EoS and hence violate the universality, but their contribution to the total network is too small to change the overall picture. The universality breaking is also observed in the spectral properties of GWs from annihilating (biased) DWs: i) the IR slope of the spectrum depends on the EoS parameter; ii) there is a plateau in the UV part of the spectrum, which gets more pronounced as one stiffens the EoS. However, the dependence on the EoS is rather weak in the near peak region, which is most relevant from the viewpoint of pulsar timing arrays and other searches for the stochastic GW background. For a selection of primordial cosmologies, we provide fitting formulae for the spectra near the peak.
↳ astro-ph.COhep-phhep-th0 citations
40
GGI Lectures on Large-Scale Structure Perturbation Theory (Effective Field Theory)
Mikhail M. Ivanov🇺🇸
These notes are an introduction to non-linear perturbation theory for cosmological large-scale structure. They are aimed at undergraduate and beginning graduate students and do not require any cosmology or quantum field theory background. All necessary concepts are developed from scratch. The lectures are intended to explain all key ingredients needed to model the observed clustering of galaxies in real and redshift spaces. After a brief pedagogical introduction to the ideas of effective field theory (EFT), we develop large-scale structure EFT in the context of Newtonian cosmology using symmetry principles. We discuss in detail the shortcomings of Standard Perturbation Theory, the non-linear evolution of baryon acoustic oscillations and its relation to the equivalence principle, counterterms and renormalization of the loop diagrams, and stochastic effects. Then we develop EFT for galaxy bias and redshift space distortions. We also highlight some important facts about redshift-space stochasticity, relevant for ongoing and future galaxy surveys. Finally, we introduce Lagrangian Perturbation Theory.
↳ astro-ph.COgr-qchep-phhep-th2 citations
41
Estimating amplitude of matter density fluctuations in solar and supernova models using neutrino flavor evolution
Caroline Laber-Smith🇺🇸 · Hansen Torres🇺🇸 · Lily Newkirk🇺🇸 · Dhriti Rathod🇺🇸 · A. Baha Balantekin🇺🇸 · Amol V. Patwardhan🇺🇸
Neutrinos can undergo substantial flavor evolution between their production in astrophysical sources-such as the Sun and core-collapse supernovae-and their subsequent detection in terrestrial detectors. This flavor evolution is strongly influenced by the environment that the neutrinos interact with, making them useful astrophysical messengers capable of potentially carrying information about the properties of the source wherein they are produced. In this work, we apply the framework of statistical data assimilation (SDA) in order to ascertain the extent to which a neutrino signal at detection may contain information about matter density fluctuations along their path from the source. Using simplified models of neutrino flavor evolution and propagation in the sun and in a core-collapse supernova (CCSN), we find that the SDA method is able to extract information about the amplitude of density fluctuations in both the solar and CCSN scenarios, with the method showing relatively greater reliability in the solar neutrino case. Nonetheless, even in the CCSN neutrino model, the method proved effective at high fluctuation amplitudes
↳ astro-ph.HEhep-phnucl-th0 citations
42
Inflation, Open Universes, and Dark Energy
Anton Chudaykin🇨🇭 · Mikhail M. Ivanov🇺🇸 · Renata Kallosh🇺🇸 · Andrei Linde🇺🇸 · Oliver H. E. Philcox🇺🇸 · Yusuke Yamada🇰🇷
We study the impact of spatial curvature ( $Ω_{k}$ ) and dynamical dark energy (parametrized by $w_{0}$ and $w_{a}$ ) on the spectral index $n_{s}$ using a combination of cosmic microwave background datasets (Planck, SPT, and ACT), and spectroscopic galaxy samples from DESI, including both BAO and full-shape clustering measurements. We show that a small negative curvature, $Ω_{k} ≃ 3 \times 1 0^{- 3}$ , lowers the value of $n_{s}$ , bringing it closer to predictions of the Starobinsky, Higgs, and simplest $α$ -attractor inflationary models. In particular, we find $n_{s} = 0.9667 \pm 0.0041$ (using Planck and DESI data) or $n_{s} = 0.9692 \pm 0.0035$ (adding ACT and SPT). Allowing for time-evolving dark energy also reduces the spectral index, leading to $n_{s} = 0.9716 \pm 0.0032$ (from the combined dataset), or $n_{s} = 0.9694 \pm 0.0035$ in combination with a small negative curvature. Our results demonstrate that the tension between current observational data and the Starobinsky, Higgs, and simplest $α$ -attractor models holds only for $Λ$ CDM, and can be mitigated in extended cosmological models. We discuss implications of these findings for inflationary models in an open universe and/or with dynamical dark energy, including scenarios with quantum tunneling and non-standard topology. Furthermore, we briefly describe a special class of $α$ -attractor models, where one can make $n_{s}$ arbitrarily large, and we describe the $α$ -attractor quintessence model. Such models may be of particular relevance when future data from DESI, as well as DESI-II, SPHEREx, Euclid, Rubin, and Roman, becomes available.
↳ astro-ph.COgr-qchep-phhep-th4 citations
43
Beyond monomial $α$ -attractors
Laura Iacconi🇬🇧
Recent small-scale CMB data show a preference for larger scalar spectral index, $n_{s}$ , when combined with DESI data. Monomial $α$ -attractor T-models can be reconciled with the new observations if the power of the hyperbolic tangent function is $p \geq 6$ , where $p$ is even. The supergravity construction of monomial T-models with $p > 2$ relies on the assumption that lower powers remain negligible over the whole field range explored during inflation and reheating. What would be the consequences of going beyond the monomial formulation? As a first step in this direction, we consider the case of a binomial potential, given by the sum of quadratic and quartic terms. When the quartic coefficient, $c$ , is $0 < c + 1/2 ≪ 1$ , we find that the new model displays non-universal behavior for $n_{s}$ , leading to values as large as $0.965$ and with an $α$ -dependence that is qualitatively different from that of monomial potentials. By solving the background dynamics during the first few e-folds of perturbative reheating we show that the quartic term might dominate before the quadratic one eventually takes over as the inflaton oscillations decrease in amplitude. This leads to a time-dependent equation of state, with $w ˉ \sim 1/3$ initially before ultimately $w ˉ \to 0$ . Obtaining a quartic-dominated reheating stage lasting $\sim 4$ e-folds requires a substantial hierarchy between the quartic and quadratic terms, $c \sim 1 0^{5}$ for $α ≳ 0.1$ . Our study highlights that models beyond the monomial form can lead to non-trivial deviations of $n_{s}$ from the predictions of monomial potentials. Furthermore our results for $w ˉ$ during reheating call into question the use of monomial models with large $p$ ; assuming that $w ˉ$ is uniquely determined by the $p$ -th power relies on substantial fine-tuning of the underlying supergravity potential.
↳ astro-ph.COgr-qchep-phhep-th1 citation
44
Dark Matter Constraints from Small-Scale Cosmic Structure
Ethan O. Nadler🇺🇸 · Keir K. Rogers🇬🇧 · Alex Drlica-Wagner🇺🇸
Small-scale cosmic structure provides a powerful test of the fundamental nature of dark matter (DM). A wide range of DM models impact matter clustering on small scales, including warm, fuzzy, and (self-)interacting DM. In these scenarios, DM physics such as free-streaming, wave interference, and self/Standard Model interactions alter the abundance and internal structure of DM halos. Cosmological and astrophysical probes of nonlinear structure---including dwarf galaxies, strong lensing, the Lyman- $α$ forest, stellar streams, and high-redshift galaxies---are therefore sensitive to these effects. Here, we review DM constraints provided by small-scale structure, focusing on observables that probe scales smaller than $\sim 1 Mpc$ , which define the frontier of current measurements. We summarize how these constraints have been translated to limits on microphysical DM models, and we discuss key modeling uncertainties and observational systematics. Finally, we highlight the growing importance of probe combination and simulation-based inference for this field, and we overview upcoming observational facilities that will sharpen small-scale structure tests of DM physics.
↳ astro-ph.COastro-ph.GAhep-ph3 citations
45
Axion Inflation with a Massive Abelian Gauge Field
Ricardo Z. Ferreira🇵🇹 · Alessio Notari🇮🇹 · José Jaime Terente Díaz🇵🇹
An axial coupling between an inflaton and an Abelian gauge field can trigger the tachyonic amplification of one gauge-field helicity. For a massless vector, modes with physical momentum $k / a \sim ∣ ξ ∣ H$ are enhanced by approximately $exp (π ∣ ξ ∣)$ , and sufficiently efficient production can provide substantial friction for the homogeneous inflaton. We extend this mechanism to a vector of mass $m$ . The instability is present only for $∣ ξ ∣ > m ˉ \equiv m / H$ , and in the heavy regime the mode amplitude scales as $exp [π (∣ ξ ∣ - m ˉ)]$ . Because the amplified modes remain well inside the Hubble radius when $m ˉ ≫ 1$ , their contribution to long-wavelength curvature perturbations is power-law suppressed at fixed background backreaction. In the weak-backreaction regime we obtain $P_{ζ}^{id} \propto m ˉ^{- 2}$ , while including the gauge-induced friction of scalar perturbations gives the scaling $P_{ζ}^{id} \propto m ˉ^{- 3}$ . These estimates indicate that $P_{ζ}^{id} ≲ 1 0^{- 9}$ on CMB scales should be compatible with gauge field backreaction for $m ˉ$ larger than order a few hundred. We test the analytical mode functions and backreaction estimates with the first lattice simulations based on a massive-vector extension of the \texttt{Pencil Code}, including simulations in the strongly backreacting regime.
↳ astro-ph.COhep-ph0 citations
46
Learning to Trace Seiberg Dualities
Jonathan J. Heckman🇺🇸 · Shani Meynet🇺🇸 · Alessandro Mininno🇺🇸 · Gary Shiu🇺🇸
Dualities play an important role in establishing both microscopic and emergent phenomena in a wide range of physical systems. In practice, though, it can often be computationally challenging to establish when two systems are dual, even when all of the "rules of the game" are well-known. Said differently, when confronted with two systems, how can one efficiently establish that they are in fact dual? In this paper we use machine learning methods to address this question for Seiberg dualities of supersymmetric quiver gauge theories. Mathematically, this involves establishing mutations of quivers, which is in turn a variation on the theme of "learning to unknot". On the one hand, this leads us to a practical tool for establishing the computational complexity of different dualities. On the other hand, it also allows us to study how different network architectures learn how to trace Seiberg dualities. We find that for quivers with a modest number of quiver nodes (of order $10$ ), different network architectures consisting of transformers and multi-layer perceptrons tend to outperform deterministic algorithms. Supplementing the network by well-established pathfinder algorithms (essentially "Google Maps for quivers") leads to an additional improvement in the efficiency and accuracy of the search strategy. We anticipate that this class of questions can serve as a useful benchmark for frontier AI models applied to theoretical physics.
↳ hep-thcs.AIcs.LGhep-ph1 citation

Affiliations

first authorsco-authorsvia INSPIRE