Thu·Mar 12, 2026Thursday·March 12, 2026

1. 01*

   Searching for axions with time resolved pulsar polarimetry

   Francesca Chadha-Day🇬🇧 · Tanmay Kumar Poddar🇬🇧

   Pulsars possess strong dipole magnetic fields that can source axion fields through the axion-photon interaction. Pulsars may therefore be surrounded by axion field configurations oscillating with the pulsar's rotational period. These axions could be detected by observing their effect on the polarization of the pular's emission. In this paper, we use time resolved observations of the optical polarization of the Crab pulsar to place bounds on the axion-photon coupling, demonstrating the potential of time resolved pulsar birefringence in the search for axions.

   hep-phastro-ph.COPRD(2026)·2 citations
2. 02*

   Mapping the critical region along the second-order chiral phase boundary

   Shi Yin🇩🇪

   We investigate the extent of the critical scaling region of the chiral phase transition at finite chemical potential within the quark-meson (QM) model using the functional renormalization group (fRG) approach. By analyzing the scaling behavior of the chiral order parameter and correlation length with respect to temperature and pion mass near the second-order phase transition, we extract critical exponents from the data and quantify the range over which the scaling relations remain valid. We find that both the leading order and the next-to-leading-order scaling regions systematically shrink as the chemical potential increases. This behavior is observed in both the local potential approximation (LPA) and its extension including anomalous dimensions (LPA'), with qualitatively consistent results, while the scaling region in LPA' is slightly smaller than that in LPA.

   hep-phhep-thPRD(2026)·0 citations
3. 03*

   Polarization structure and spin covariance of massive vector-boson amplitudes in QCD

   Giuseppe De Laurentis🇬🇧 · Kirill Melnikov🇩🇪 · Matteo Tresoldi🇩🇪

   Nearly thirty years ago, Bern, Dixon and Kosower computed all helicity amplitudes for the annihilation of an electron-positron pair into four QCD partons through an electroweak vector boson. More recently, the leading-color two-loop amplitudes for the same process were obtained. When such amplitudes are expressed in the massless spinor-helicity formalism, they effectively correspond to the decay of a transversely polarized vector boson. However, for several reasons, it is highly desirable to extend these calculations to the case where the polarization of the vector boson is longitudinal. Due to the complexity of such computations, repeating them to obtain the result for the ''missing'' polarization of the electroweak boson is a significant undertaking even at one loop. Besides, when attempting new higher-loop computations, it is beneficial to identify the minimal set of quantities (e.g. form factors) that must be determined to obtain the full amount of physically-relevant information. In this paper, we show that amplitudes involving vector-boson decays to massless leptons-although they appear to project onto the transverse polarization-still encode the full information about all polarization states of the vector boson, including the longitudinal one. This follows from the little-group (spin) covariance of the amplitude, which allows us-largely through simple replacement rules-to rewrite the helicity amplitudes as a matrix with open SU(2) spin indices in the massive spinor-helicity (or spin-spinor) formalism. Therefore, knowledge of an amplitude for any polarization component suffices to reconstruct the full covariant matrix.

   hep-phJHEP(2026)·1 citation
4. 04*

   The phenomenon of the axion kinetic misalignment with a generic PQ-breaking operator

   Xiangwei Yin🇨🇳 · Ligong Bian🇨🇳

   We investigate the phenomenology induced by generic PQ-breaking operators within the axion kinetic misalignment framework. We analyze their impact on the relic density of axion dark matter (DM), the PQ quality problem, axion-mediated fifth-force, as well as Big Bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) constraints. A nonzero initial axion velocity gives rise to brief periods of early matter domination and axion kinetic domination, leading to a nonstandard cosmological evolution. We compute the resulting gravitational wave (GW) signal from global cosmic strings and find that, because these nonstandard epochs are extremely short, the signal is highly suppressed and beyond the reach of existing experiments. Finally, we perform a parameter space scan, identify the regions and benchmark point that are consistent with all experimental constraints.

   hep-phastro-ph.HE1 citation
5. 05*

   Quark spin correlation inside hyperons

   Lucia Oliva🇮🇹 · Qun Wang🇨🇳 · Xin-Nian Wang🇨🇳

   The global spin polarization of hyperons in heavy-ion collisions have been investigated by including spin correlation effects among their constituent quarks. The available data on global spin polarizations of hyperons and spin alignments of vector mesons provide constraints on phase space functions of the spin polarization and correlation. These constraints can lead to inequalities under some approximations, which might provide possible clues for the presence of quark spin correlation inside hyperons at lower collision energies.

   hep-phPRC(2026)·5 citations
6. 06*

   Discriminating Dark Matter Origins with Directional Detection

   Nicole F. Bell🇦🇺 · Chiara Lisotti🇦🇺 · Jayden L. Newstead🇦🇺 · Ciaran A. J. O'Hare🇦🇺 · Iman Shaukat Ali🇦🇺

   Scenarios where dark matter is boosted to relativistic velocities provide a promising probe of sub-GeV dark matter. Cosmic-ray upscattered and supernova-produced dark matter generate relativistic fluxes peaked toward the Galactic Centre, an anisotropy that offers a strong directional signature and is not mimicked by any terrestrial or cosmic background. We determine how many directional recoil events are required in a gas time-projection chamber to distinguish various scenarios for the origin of dark matter particles arriving in the solar system, which are otherwise indistinguishable without directionality. We find that standard halo dark matter particles can be distinguished from boosted populations with as few as $\mathcal{O}(20)$ events under reasonable track reconstruction performance and background conditions.

   hep-ph0 citations
7. 07*

   Three-gluon decays of radially excited quarkonia $\psi (2S)$ and ${\rm Y}(2S)$ with both relativistic and QCD radiative corrections

   Chao-Jie Fan🇨🇳 · Jun-Kang He🇨🇳

   For the radially excited heavy quarkonia $V=\psi (2S)$ and ${\rm Y}(2S)$, the nodal structure of the wave function renders the three-gluon decay $V\to ggg$ acutely sensitive to relativistic corrections, a longstanding challenge for reliable theoretical predictions. Within the Bethe-Salpeter formalism under the covariant instantaneous ansatz, we construct analytic harmonic-oscillator wave functions incorporating the $2S$ node and derive model-independent relations among the polarized decay widths from helicity-flip and phase-space symmetries. Motivated by the strikingly slow ${\hat{q}}^2$-order convergence driven by destructive interference at the node, we introduce a concise phenomenological treatment of the higher-order contributions that preserves the correct low-momentum limit. Including both relativistic and QCD radiative corrections, our predictions for $\Gamma (V\to ggg)$, $\Gamma (V\to e^{+}{e}^{-})$ and $R_V$ agree well with experiment, and the extracted ${\beta }_V$ lies at the lower end of typical phenomenological ranges, reflecting a more localized momentum-space wave function.

   hep-phPRD(2026)·1 citation
8. 08*

   Heavy-quark contributions to the polarized DIS structure functions at NLO in the ACOT scheme

   Edoardo Spezzano🇩🇪 · Tomas Jezo🇩🇪 · Michael Klasen🇩🇪 · Ingo Schienbein🇫🇷

   This study explores the heavy-quark contributions to polarized structure functions in deep-inelastic scattering at next-to-leading order. The structure functions $g_1$, $g_4$, $g_5$, $g_6$, and $g_7$ are computed, while $g_2$ and $g_3$ are excluded due to the higher-twist suppression. The calculations are performed within the ACOT renormalization scheme, which ensures theoretical consistency across kinematic regions where heavy quarks transition from being dynamically produced to fully active degrees of freedom. By incorporating heavy-flavor contributions at next-to-leading-order, this work provides deeper insights into their role in polarized structure functions and the spin-dependent dynamics of QCD. Both analytical results and their numerical implementation are presented.

   hep-phJHEP(2026)·0 citations
9. 09*

   Fragmentation contributions to transverse nucleon spin observables in semi-inclusive deep-inelastic scattering at NLO

   Diego Scantamburlo🇩🇪 · Marc Schlegel🇩🇪

   We study the spin-dependent cross section in semi-inclusive deep-inelastic lepton-nucleon collisions, $\ell +N^{\uparrow }\to \ell +h+X$. We focus on the cross section that is integrated over the transverse momentum $P_{h\perp }$ of the detected unpolarized hadron. We analyze this cross section at large virtuality $Q^2$ of the exchanged virtual photon within the framework of collinear twist-3 factorization in perturbative QCD. The two main transverse spin observables, the single nucleon spin asymmetry (SSA) and the double longitudinal lepton-transverse nucleon spin asymmetry (DSA), both receive contributions from chiral-odd twist-3 three-parton fragmentation functions. We study these fragmentation contributions to Next-To-Leading Order (NLO) in perturbative QCD. We explicitly observe that collinear twist-3 factorization holds for these contributions at the one-loop level. We confront our NLO formulae with HERMES data and provide numerical predictions for EIC kinematics.

   hep-phhep-exPRD(2026)·1 citation
10. 10*

    Analysis of the hidden-charm pentaquark candidates in the $J/\psi \Sigma$ mass spectrum via the QCD sum rules

    Zhi-Gang Wang🇨🇳 · Yang Liu🇨🇳

    In this work, we adopt the diquark model, construct the diquark-diquark-antiquark type currents with the light quarks $uus$ in two octets, and study the $uusc\bar{c}$ pentaquark states in the framework of the QCD sum rules systematically. We obtain the mass spectrum of the hidden-charm-singly-strange pentaquark states with the quantum numbers $I{J}^P=1{\frac{1}{2}}^{-}$, $1{\frac{3}{2}}^{-}$ and $1{\frac{5}{2}}^{-}$. And we can search for those $P_{cs}$ states in the processes ${\Sigma }_b^{+}\to P_{cs}^{+}\varphi \to J/\psi {\Sigma }^{+}\varphi$ and ${\Xi }_b^0\to P_{cs}^{+}{K}^{-}\to J/\psi {\Sigma }^{+}{K}^{-}$.

    hep-phFront.Phys.(2027)·6 citations
11. 11*

    Systematic exploration of triply heavy tetraquarks: spectroscopic and decay characteristics

    Hong-Tao An🇨🇳 · Yu-Shuai Li🇨🇳 · Si-Qiang Luo🇨🇳

    While hidden, singly, doubly, and fully heavy tetraquark states have been experimentally observed, triply heavy tetraquark states remain experimentally unconfirmed. We systematically investigate the spectroscopic and decay properties of four triply heavy-flavor tetraquark systems ($cc\bar{c}\bar{n}$, $cc\bar{c}\bar{s}$, $bb\bar{b}\bar{n}$, $bb\bar{b}\bar{s}$; $n=u,d$) based on the nonrelativistic quark model. Using an effective Hamiltonian, we employ the Gaussian expansion method to solve the four-body Schrödinger equation and incorporate the effect of color-spin configuration mixing. Results show both $cc\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$ systems have two $J^P=0^{+}$, three $J^P=1^{+}$, and one $J^P=2^{+}$ states, with ground-state masses of 5.2-5.5 GeV and 15.0-15.3 GeV, respectively. Root-mean-square radius analysis supports compact tetraquark configurations. All states are unstable, with rearrangement strong decays dominant and negligible radiative decays. Narrow resonances (e.g., $T_{c^2\bar{c}\bar{s}}(5360,0^{+})$, $T_{b^2\bar{b}\bar{n}}(15148,2^{+})$) arise from Feynman amplitude cancellation. We propose experimental searches in $J/\psi D_s^{\ast }$/ ${\eta }_c{D}_s$ (5.3-5.4 GeV) and ${\rm Y}{B}^{\ast }$ (15.1-15.2 GeV) channels, providing key guidance for triply heavy tetraquark identification.

    hep-phEPJC(2026)·1 citation
12. 12*

    Isentropic thermodynamics across the hadron-quark mixed phase in a two-phase model with a PNJL quark description

    Eduardo L. G. Salgado🇵🇹 · Pedro Costa🇵🇹 · Constança Providência🇵🇹

    We study the hadron-quark mixed phase within a two-phase model for symmetric and asymmetric matter. For the quark sector we employ the (2+1) Polyakov-extended Nambu-Jona-Lasinio model (PNJL) with vector interactions. We investigate how the hadronic equation of state affects the phase diagram and the thermodynamic properties inside the mixed phase. The behavior of isentropic trajectories in the mixed phase depends on the fixed entropy per baryon ($s/{\rho }_B$), with trajectories near the critical end point (CEP) exhibiting a pronounced cooling pattern, while isentropic trajectories with low entropy per baryon undergo pronounced heating as the baryonic density increases. The adiabatic squared speed of sound displays characteristic peak and dip structures that depend on $s/{\rho }_B$. The polytropic index along isentropic and isothermal trajectories, including in the vicinity of the CEP are also investigated. The effects of vector interactions and isospin asymmetry on thermodynamic observables likewise depend on the chosen $s/{\rho }_B$ value. Finally, we discuss the population of hyperons along isentropic trajectories and their influence on the phase diagram. The main effect of hyperons is to shift the onset of deconfinement to larger densities and decrease the density extension of the mixed phase.

    hep-phnucl-thPRD(2026)·0 citations
13. 13*

    Cross-Environment Diagnostics for New Physics in Proton-Proton and Heavy-Ion Collisions

    Yi Yang🇹🇼

    Proton-proton and heavy-ion measurements are usually interpreted within separate theoretical and experimental frameworks, even when the same reconstructed final state is measured and the $pp$ result provides or constrains the elementary reference for nuclear observables. This separation creates a potential blind spot: an omitted contribution can be absorbed into production or signal-model parameters in $pp$ collisions and then be reinterpreted through independent nuclear-medium parameters in heavy-ion collisions. We propose cross-environment closure as a complementary search principle. Conventional parameters remain specific to each collision system, while one candidate new-physics contribution must remain coherent across systems and observables. Quarkonium is used as a controlled illustration rather than as the definition of the method. A near-degenerate dimuon component is shown to be absorbable into a retuned $pp$ spectrum and a single-peak mass fit, while the same $p_T$-dependent contribution propagates into representative $R_{pA}$, $R_{AA}$, and $v_2$ relations. These quantities are consistency observables, not assumed new-physics baselines. The numerical examples are stress tests, not claims about an allowed particle or an anomaly in current data. The main result is a transferable diagnostic principle, illustrated here with quarkonium rather than formulated as a universal statistical framework.

    hep-phhep-exnucl-exnucl-th0 citations
14. 14*

    Phase structure and observables at high densities from first principles QCD

    Christian S. Fischer🇩🇪 · Jan M. Pawlowski🇩🇪

    We provide a short review of the progress made in the past decade with functional QCD in the description of the phase structure of QCD. We summarise the most important technical aspects of the framework, discuss strategies for truncations and address the problem of systematic error estimates. We detail efforts to gauge the approach systematically with lattice QCD at zero chemical potential, also including the physics of the Columbia plot at non-physical quark masses. Our main focus is, however, the high density regime of QCD. We address the predictive power of the functional approach for the appearance of new phases beyond the chiral crossover regime for chemical potentials ${\mu }_B/T\ge 4.5$. The onset of this regime may be signalled by a critical end point of the crossover line but may also involve a moat regime or the emergence of an instability that indicates an inhomogeneous phase. Respective results include estimates for the location of the onset of new phases, and predictions for their experimental signatures.

    hep-phhep-exhep-latnucl-th22 citations
15. 15*

    Intrinsic Nonlocality of Spin- and Polarization-Resolved Probabilities in Strong-Field Quantum Electrodynamics

    Samuele Montefiori🇩🇪 · Antonino Di Piazza🇺🇸 · Tobias Podszus🇩🇪 · Christoph H. Keitel🇩🇪 · Matteo Tamburini🇩🇪

    Spin and polarization are central to precision tests of fundamental physics and for interpreting radiation from astrophysical sources and ultraintense laser-matter experiments. Here, focusing on the fundamental process of nonlinear Compton scattering, we demonstrate that a key assumption underlying current strong-field quantum electrodynamics (SFQED) models, i.e., that emission can be treated as an instantaneous random event sampled from a local differential rate, is inconsistent once emission angles, electron spin, and/or photon polarization are resolved. Namely, even in strictly constant and uniform fields, the resulting fully differential distribution is sign-indefinite, yielding negative inferred probabilities. The physical reason is that the photon emission probability builds up over a finite length of the electron trajectory, the formation region, during which the electron direction changes by roughly the same small angle that defines the radiation cone. Therefore, we put forward a new method where we integrate over this formation region analytically to obtain a physically consistent electron spin and photon polarization model. Simulations of a GeV-class electron-laser collision accessible at current petawatt facilities and of emission in a pulsar-like magnetic field are shown to reveal spin and polarization patterns that differ even qualitatively from state-of-the-art local models. In particular, our new model predicts substantial angle-dependent circular photon polarization where the well-known collinear-emission approach yields none, and a pronounced helicity bias in the recoiling electrons absent from current predictions. These findings have direct implications for upcoming strong-field QED experiments and for interpreting polarized radiation from extreme astrophysical environments.

    hep-phastro-ph.HEphysics.plasm-phPRD(2026)·2 citations
16. 16*

    Dispersive Analysis of $D$- and $B$-Meson Form Factors with Chiral and Heavy-Quark Constraints

    Simon Mutke🇩🇪 · Leon A. Heuser🇩🇪 · Ingrid Dax🇩🇪 · Bastian Kubis🇩🇪 · Stefan Leupold🇸🇪

    We analyze the isovector vector form factors of $D$, $D^{\ast }$, $B$, and $B^{\ast }$ mesons at low energies. We employ all constraints due to chiral and heavy-quark symmetry, and include the physics of resonant pion-pion rescattering in a model-independent way, using dispersion theory. Special attention is paid to the analytic properties of these form factors, which include anomalous thresholds due to triangle diagrams that are located on the physical Riemann sheets in some of the form factors. We extract the couplings of the $\rho (770)$ resonance to all these heavy mesons by determining the appropriate pole residues.

    hep-phhep-exnucl-thEPJC(2026)·1 citation
17. 17*

    Comprehensive Effective Field Theory Analysis for Baryon Number Violating Processes

    Chuan-Qiang Song🇨🇳 · Jiang-Hao Yu🇨🇳

    Baryon number-violating processes arise generically in many extensions of the Standard Model, with Grand Unified Theories providing the most compelling realizations. Ongoing experimental searches at JUNO, Hyper-K, and DUNE motivate a more precise and model-independent analysis utilizing the effective field theory (EFT) framework capable of connecting ultraviolet dynamics to low-energy hadronic observables. In this work, we perform a pipeline analysis that connects baryon number-violating (BNV) new physics to its low-energy description through the Standard Model EFT (SMEFT) up to dimension nine and the Low-Energy EFT (LEFT) up to dimension eight, and subsequently matches onto chiral perturbation theory using a systematic spurion method. We show that the complete set of dimension-eight LEFT operators enables the inclusion of the full set of chiral representations for three-quark operators with derivatives, which are also embedded in the chiral Lagrangian after quark-hadron matching. By contrast, the conventional dimension-six operators generate only the $(\bar{3},3)$ and $(8,1)$ representations. The higher dimensional LEFT operators should be matched from higher order SMEFT operators, and thus a wider class of UV completions are allowed. We consider the complete tree-level UV resonances for dimension 6 and 7 SMEFT operators, and representative UVs for higher dimension operators.

    hep-phnucl-th2 citations
18. 18*

    Polarized Target Nuclear Magnetic Resonance Measurements with Deep Neural Networks

    Devin Seay🇺🇸 · Ishara P. Fernando🇺🇸 · Dustin Keller🇺🇸

    Continuous-wave Nuclear Magnetic Resonance (CW-NMR) operated in constant-current mode has served as a foundational technique for polarization measurement in solid-state dynamically polarized targets within nuclear and high-energy physics experiments for several decades, and it remains an essential tool. Conventional Q-meter-based phase-sensitive detection is critical for precise real-time determination of target polarization during scattering runs. However, the accuracy and reliability of these measurements are frequently compromised by elevated noise levels, baseline drift, and systematic uncertainties arising from signal isolation and fitting, ultimately degrading the overall experimental figure of merit. In this work, we report the first successful application of neural network architectures to continuous-wave NMR polarization metrology. By leveraging advanced machine learning techniques for signal extraction and denoising, we achieve a substantial reduction of fitting uncertainties under a variety of realistic simulated and experimental conditions. These improvements translate directly into more robust real-time (online) polarization monitoring and higher precision in subsequent offline analysis. By reducing analysis-induced uncertainty, the resulting methodology can improve the effective figure of merit for scattering experiments employing dynamically polarized targets and provides a new toolset for NMR-based polarimetry in high-energy and nuclear physics.

    ↳ physics.ins-dethep-phEPJA(2026)·0 citations
19. 19*

    Measuring neutrino mass in light of ACT DR6 and DESI DR2

    Lu Feng🇨🇳 · Tian-Nuo Li🇺🇸 · Guo-Hong Du🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    The recent release of high-precision cosmological data, particularly the small-scale cosmic microwave background (CMB) measurements from ACT and baryon acoustic oscillation (BAO) data from DESI, has opened a new landscape for probing the neutrino mass. In this work, we present updated constraints on the total neutrino mass, $\sum m_{\nu }$, and its hierarchy within the $\Lambda$CDM, $w$CDM, holographic dark energy (HDE), and $w_0{w}_a$CDM models, using the latest ACT DR6, DESI DR2, and DESY5 datasets. We find that the upper limits on $\sum m_{\nu }$ are critically governed by the evolutionary behavior of the dark energy equation of state. Specifically, models exhibiting early-time quintessence features (e.g., HDE) yield the most stringent constraints, whereas those allowing for early-time phantom behavior (e.g., $w_0{w}_a$CDM) result in significantly looser bounds. Despite these model-dependent variations, we observe a robust hierarchy dependence across all scenarios, where the inverted hierarchy consistently yields weaker constraints and the degenerate hierarchy consistently yields tightest constraints. Our analysis demonstrates that the improved small-scale CMB information from ACT, combined with high-precision BAO data, systematically tightens the limits on $\sum m_{\nu }$, providing a crucial benchmark for future neutrino mass measurement.

    ↳ astro-ph.COgr-qchep-phPhys.Dark Univ.(2026)·13 citations
20. 20*

    Naturally Light Distortion

    Kazunori Nakayama🇯🇵

    In the most general formulation of gravity, the metric and connection are independent degrees of freedom, and the connection may include torsion and non-metricity (or distortion, collectively) degrees of freedom, resulting in a huge number of possible dynamical fields. However, the most fields are either non-dynamical or extremely heavy and the general relativity is recovered at low energy. We find a unique naturally light vector- or scalar-like distortion field, which can be dynamical and have phenomenological implications. In particular, a light scalar particle that mixes with the Higgs boson naturally appears.

    ↳ gr-qchep-phhep-th1 citation
21. 21*

    Learning to Unscramble: Simplifying Symbolic Expressions via Self-Supervised Oracle Trajectories

    David Shih🇺🇸

    We present a new self-supervised machine learning approach for symbolic simplification of complex mathematical expressions. Training data is generated by scrambling simple expressions and recording the inverse operations, creating oracle trajectories that provide both goal states and explicit paths to reach them. A permutation-equivariant, transformer-based policy network is then trained on this data step-wise to predict the oracle action given the input expression. We demonstrate this approach on two problems in high-energy physics: dilogarithm reduction and spinor-helicity scattering amplitude simplification. In both cases, our trained policy network achieves near perfect solve rates across a wide range of difficulty levels, substantially outperforming prior approaches based on reinforcement learning and end-to-end regression. When combined with contrastive grouping and beam search, our model achieves a 100\% full simplification rate on a representative selection of 5-point gluon tree-level amplitudes in Yang-Mills theory, including expressions with over 200 initial terms.

    ↳ hep-thcs.LGcs.SChep-ph6 citations
22. 22*

    Spontaneous Baryogenesis and Primordial Black Hole Dark Matter from Ultra-Slow-Roll Inflation

    Shyam Balaji🇬🇧

    We propose a unified framework where the totality of dark matter (DM), the baryon asymmetry of the universe, and a detectable stochastic gravitational wave (GW) background originate from ultra-slow-roll (USR) inflation. The drastic suppression of the inflaton velocity during the USR phase, required for primordial black hole (PBH) DM production, can also set the initial conditions for spontaneous baryogenesis via a derivative coupling. This mechanism establishes a predictive correlation between the PBH abundance and the baryon yield, effectively fixing the reheating temperature $T_{\text{reh}}$ as a function of the post-peak spectral slope of the primordial power spectrum and the tensor-to-scalar ratio on CMB scales $r_{\text{CMB}}$. We perform a simple scan of the parameter space, demonstrating that while ``flat'' spectral tails allow for high-scale inflation ($r_{\mathrm{CMB}}\lesssim 10^{-3}$, $T_{\mathrm{reh}}\lesssim 10^{14}\text{ GeV}$) with a small wedge of tensor-to-scalar ratios potentially accessible to future CMB B-mode experiments, steep spectral tails enforce drastically lower scale inflation with an unobservably small $r_{\mathrm{CMB}}$ to avoid baryon overproduction. This degeneracy can be broken by GW astronomy: while LISA and DECIGO are capable of detecting the induced GW background associated with asteroid-mass PBH DM, the Einstein Telescope (ET) can act as a spectral discriminator, sensitive only to the broadband signals of high-scale scenarios.

    ↳ astro-ph.COhep-ph0 citations
23. 23*

    Imprints of Reheating Dynamics on Gravitational Waves from Phase Transitions

    Basabendu Barman🇮🇳 · Maciej Kierkla🇸🇪 · Marek Lewicki🇵🇱 · Marco Merchand🇯🇵

    We investigate how perturbative reheating after inflation modifies the primordial gravitational wave (GW) spectrum generated by cosmological phase transitions. Within a specific inflationary setup, we show that the thermodynamic quantities that control the phase transition depend on the effective equation of state of the cosmological background, which is itself set by the form of the inflaton potential during reheating. Assuming reheating proceeds via perturbative dissipation of the inflaton condensate into boson or fermion pairs, we find that phase transitions taking place in this epoch generally produce GW signals that are systematically suppressed compared with the standard radiation-dominated scenario. We also identify characteristic spectral features that may arise in this case, which could serve as distinctive signatures of the modified expansion history during reheating.

    ↳ astro-ph.COhep-phPRD(2026)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.