Thu·Jun 22, 2023Thursday·June 22, 2023

1. 01*

   Light long-lived particles at the FCC-hh with the proposal for a dedicated forward detector FOREHUNT and a transverse detector DELIGHT

   Biplob Bhattacherjee🇮🇳 · Herbi K. Dreiner🇩🇪 · Nivedita Ghosh🇮🇳 · Shigeki Matsumoto🇯🇵 · Rhitaja Sengupta🇩🇪 · Prabhat Solanki🇮🇳

   In this paper, we propose a dedicated forward detector, FOREHUNT (FORward~Experiment~for~HUNdred~TeV), for 100 TeV FCC-hh for the detection of light long-lived particles (LLP) coming from $B$-meson decay. We calculate the signal acceptance as a function of mass and proper decay length of the LLP for 100 TeV and interpret our result in terms of model parameters for models of dark Higgs scalar and heavy neutral leptons. We also compare the sensitivity with proposed transverse detectors like MATHUSLA, CODEX-b for HL-LHC, and DELIGHT (Detector for long-lived particles at high energy of 100 TeV) for FCC-hh. Our analysis reveals that if the LLP is light ($\lesssim 4.4$ GeV) and has a low proper decay length ($<10$ m), a forward detector like FOREHUNT is the best option to look for the decaying LLP, while DELIGHT is preferable for higher proper decay lengths.

   hep-phhep-exPRD(2024)·18 citations
2. 02*

   Higgs Footprints of Hefty ALPs

   Anisha🇬🇧 · Supratim Das Bakshi🇪🇸 · Christoph Englert🇬🇧 · Panagiotis Stylianou🇩🇪

   We discuss axion-like particles (ALPs) within the framework of Higgs Effective Field Theory, targeting instances of close alignment of ALP physics with a custodial singlet character of the Higgs boson. We tension constraints arising from new contributions to Higgs boson decays against limits from high-momentum transfer processes that become under increasing control at the LHC. Going beyond leading-order approximations, we highlight the importance of multi-top and multi-Higgs production for the pursuit of searches for physics beyond the Standard Model extensions.

   hep-phhep-exPRD(2023)·5 citations
3. 03*

   Search for the anomalous quartic gauge couplings through $Z\gamma$ production at $e^{-}{e}^{+}$ colliders

   M. Köksal🇹🇷

   Spontaneous breaking of the $SU(2{)}_L\times U(1{)}_Y$ electroweak symmetry of the Standard Model (SM) sets the constraints on triple gauge couplings and quartic gauge couplings. Therefore, the measurement of multiboson production in $e^{-}{e}^{+}$ collisions allows us to directly examine the SM predictions and perform indirect investigations of new physics beyond the SM. In this paper, we concentrate the process $e^{-}{e}^{+}\to e^{-}Z\gamma e^{+}$ with $Z$ boson decaying to neutrinos to investigate the anomalous quartic gauge couplings using the effective Lagrangian approach at the Compact Linear Collider (CLIC). We obtain the sensitivities on the anomalous $f_{Ti}/{\Lambda }^4$ ($i=0,2,5,6,7,8,9$) couplings taking into account the systematic uncertainties of $3,5\%$ at $95\%$ Confidence Level for the CLIC with $\sqrt{s}=3$ TeV. Our results show that the sensitivities on some anomalous couplings without systematic errors are up to two orders of magnitude better than the current experimental limits. Considering a realistic systematic uncertainty such as $5\%$ from possible experimental sources, the sensitivity of all anomalous quartic couplings gets worse by about $10\%$ compared to those without systematic uncertainty for the CLIC.

   hep-phJ.Phys.G(2024)·4 citations
4. 04*

   Multiplicity distribution and entropy of produced gluons in deep inelastic scattering at high energies

   Eugene Levin (Tel Aviv U./UTFSM)🇮🇱

   In this paper we found the multiplicity distribution of the produced gluons in deep inelastic scattering at large $z=\ln {\text{LbQ}}_s^2/Q^2\text{Rb}\gg 1$ where $Q_s$ is the saturation momentum and $Q^2$ is the photon virtuality. It turns out that this distribution at large $n>\bar{n}$ almost reproduces the KNO scaling behaviour with the average number of gluons $\bar{n}\propto \exp \text{Lb}{z}^2/2\kappa \text{Rb}$, where $\kappa =4.88$ in the leading order of perturbative QCD. TheKNO function $\Psi \text{Lb}\frac{n}{\bar{n}}\text{Rb}=\exp \text{Lb}-n/\bar{n}\text{Rb}$. For $n<\bar{n}$ we found that ${\sigma }_n\propto (z-\sqrt{2\kappa \ln (n-1)})/(n-1)$. Such small $n$ determine the value of entropy of produced gluons $S_E=0.3z^2/(2\kappa )$ at large $z$. The factor $0.3$ stems from the non-perturbative corrections that provide the correct behaviour of the saturation momentum at large $b$.

   hep-phEPJC(2024)·10 citations
5. 05*

   Superscaling in the resonance region for neutrino-nucleus scattering: The SuSAv2-DCC model

   J. Gonzalez-Rosa · G. D. Megias · J. A. Caballero · M. B. Barbaro

   In this work the SuSAv2 and dynamical coupled-channels (DCC) models have been combined and tested in the inelastic regime for electron and neutrino reactions on nuclei. The DCC model, an approach to study baryon resonances through electron and neutrino induced meson production reactions, has been implemented for the first time in the SuSAv2-inelastic model to analyze the resonance region. Within this framework, we also present a novel description about other inelasticities in the resonance region (SoftDIS). The outcomes of these approaches are firstly benchmarked against (e,e') data on 12C. The description is thus extended to the study of neutrino-nucleus inclusive cross sections on 12C and 40Ar and compared with data from the T2K, MicroBooNE, ArgoNEUT and MINERvA experiments, thus covering a wide kinematical range.

   hep-phnucl-thPRD(2023)·12 citations
6. 06*

   Left-Right Symmetry at FCC-hh

   Miha Nemevšek🇸🇮 · Fabrizio Nesti🇮🇹

   We study the production of right-handed $W_R$ bosons and heavy neutrinos $N$ at a future 100 TeV high energy hadron collider in the context of Left-Right symmetry, including the effects of $W_L-W_R$ gauge-boson mixing. We estimate the collider reach for up to 3/ab integrated luminosity using a multi-binned sensitivity measure. In the Keung-Senjanović and missing energy channels, the 3$\sigma$ sensitivity extends up to $M_{W_R}=35$ and 37 TeV, respectively. We further clarify the interplay between the missing energy channel and the (expected) limits from neutrinoless double beta decay searches, Big Bang nucleosynthesis and dark matter.

   hep-phhep-exPRD(2023)·19 citations
7. 07*

   Testing $\chi$PT with the masses of the Nambu-Goldstone bosons

   H. Leutwyler (Berrn U.)🇨🇭

   The spontaneous breakdown of an approximate symmetry implies that the spectrum of the theory contains approximately massless particles. The hidden symmetry very strongly constrains their masses. A numerical evaluation of these constraints on the lattice would allow a more precise determination of the quark mass ratios m_u:m_d:m_s and thereby reduce some of the uncertainties encountered in precision flavour physics.

   hep-phhep-latInt.J.Mod.Phys.A(2024)·2 citations
8. 08*

   Reconstruction of rational functions made simple

   Xiao Liu🇬🇧

   We present a new method for the reconstruction of rational functions through finite-fields sampling that can significantly reduce the number of samples required. The method works by exploiting all the independent linear relations among target functions. Subsequently, the explicit solutions of the functions can be efficiently obtained by solving the linear system. As a first application, we utilize the method to address various examples within the context of Feynman integrals reduction. These examples demonstrate that our method can substantially improve the computational efficiency, making it useful for future computations in particle physics.

   hep-phhep-thPLB(2024)·22 citations
9. 09*

   Best-case scenarios for neutrino capture experiments

   Kyrylo Bondarenko🇮🇹 · Alexey Boyarsky🇳🇱 · Josef Pradler🇦🇹 · Anastasia Sokolenko🇺🇸

   A direct discovery of the cosmic neutrino background would bring to a closure the searches for relic left-over radiation predicted by the Hot Big Bang cosmology. Recently, the KATRIN experiment put a limit on the local relic neutrino overdensity with respect to the cosmological predicted average value at $\eta \lesssim 10^{11}$ [Phys. Rev. Lett. 129, 011806 (2022)]. In this work, we first examine to what extent such values of $\eta$ are conceivable. We show that even under cavalier assumptions, a cosmic origin of $\eta \gtrsim 10^4$ seems out of reach (with the caveat of forming bound objects under a new force,) but find that a hypothetical local source of low-energy neutrinos could achieve $\eta \sim 10^{11}$. Second, when such values are considered, we point out that the experimental signature in KATRIN and other neutrino-capture experiments changes, contrary to what has hitherto been assumed. Our results are model-independent and maximally accommodating as they only assume the Pauli exclusion principle. As intermittent physics target in the quest for C$\nu$B detection, we identify an experimental sensitivity to $\eta \sim 10^4$ for which conceivable sources exist; to resolve the effect of a degenerate Fermi gas for such overdensity an energy resolution of 10 meV is required.

   hep-phastro-ph.COJCAP(2023)·13 citations
10. 10*

    Gravitational waves from axions annihilation through quantum field theory

    Jing Yang🇨🇳 · Fa Peng Huang🇨🇳

    We use the scattering method to calculate the gravitational wave from axions annihilation in the axion cloud formed by the superradiance process around the Kerr black hole. We consider axions annihilating to gravitons as a three-body decay process and then calculate the corresponding decay width. In this approach, we can simply obtain the radiation power of gravitational wave and give the analytical approximate result with the spin effects of the Kerr black hole. Our study can also provide a cross-check to the numerical results in the traditional method.

    hep-phPRD(2023)·16 citations
11. 11*

    Phase structure of the on-shell parametrized 2+1 flavor Polyakov quark-meson model

    Suraj Kumar Rai🇮🇳 · Vivek Kumar Tiwari🇮🇳

    Augmenting the improved chiral effective potential of the on-shell renormalized 2+1 flavour quark-meson (RQM) model with the Polyakov-loop potential that accounts for the deconfinement transition,~we get the Quantum Chromodynamics (QCD) like framework of the renormalized Polyakov quark-meson (RPQM) model.~When the divergent quark one-loop vacuum term is included in the effective potential of the quark-meson (QM) model,~its tree level parameters or the parameters fixed by the use of meson curvature masses,~become inconsistent as the curvature masses involve the self energy evaluations at zero momentum.~Using the modified minimal subtraction method,~the consistent chiral effective potential for the RQM model has been calculated after relating the counterterms in the on-shell (OS) scheme to those in the $\overline{\text{MS}}$ scheme and finding the relations between the renormalized parameters of both the schemes where the physical (pole) masses of the $\pi ,K,\eta$ and ${\eta }^{\prime }$ pseudo-scalar mesons and the scalar $\sigma$ meson,~the pion and kaon decay constants,~have been put into the relation of the running couplings and mass parameter.~Using the RPQM model and the PQM Model with different forms for the Polyakov-loop potentials in the presence or the absence of the quark back-reaction,~we have computed and compared the effect of the consistent quark one-loop correction and the quark back-reaction on the scaled chiral order parameter,~the QCD phase diagrams and the different thermodynamic quantities.~The results have been compared with the 2+1 flavor lattice QCD data from the Wuppertal-Budapest collaboration \{JHEP 09,73(2010); PLB 730,99(2014)\} and the HotQCD collaboration \{PRD 90,094503(2014)\}.

    hep-phnucl-thPRD(2024)·10 citations
12. 12*

    Spin Partners of the $B^{(\ast )}{\bar{B}}^{(\ast )}$ resonances with a different approach than the Breit-Wigner parameterization

    Duygu Yıldırım🇹🇷

    In general, resonances are obtained by the Breit-Wigner parameterization. However, it is not entirely appropriate to use this parameterization with near-threshold resonances such as the $Z_b(10610)$ and the $Z_b(10650)$, as Breit-Wigner does not contain the threshold effect. To eliminate this defect, a recently proposed alternative distribution, the Sill, is used to predict possible heavy quark spin symmetry partners of the $Z_b(10610)$ and the $Z_b(10650)$. With the Sill values of the $Z_b(10650)$ and the $Z_b(10610)$ states, assuming these exotics generate molecular states consisting of contact and a pion exchange potential, heavy quark spin symmetry partners are examined with $S$ and $D$-wave contributions. In the light of the Sill type resonance approach, all the partners are found as bound states.

    hep-phEPJA(2023)·4 citations
13. 13*

    New insight into the exotic states strongly coupled with the $D{\bar{D}}^{\ast }$ from the $T_{cc}^{+}$

    Guang-Juan Wang🇯🇵 · Zhi Yang🇨🇳 · Jia-Jun Wu🇨🇳 · Makoto Oka🇯🇵 · Shi-Lin Zhu🇨🇳

    We have investigated the internal structure of the open- and hidden-charmed ($D{D}^{\ast }$/$\bar{D}{D}^{\ast }$) molecules in the unified framework. We first fit the experimental lineshape of the $T_{cc}^{+}$ state and extract the $D{D}^{\ast }$ interaction, from which the $T_{cc}^{+}$ is assumed to arise solely. Then we obtain the $D{\bar{D}}^{\ast }$ interaction by charge conjugation. Our results show that the $D{\bar{D}}^{\ast }$ interaction is attractive but insufficient to form $X(3872)$ as a bound state. Instead, its formation requires the crucial involvement of the coupled channel effect between the $D{\bar{D}}^{\ast }$ and $c\bar{c}$ components, although the $c\bar{c}$ accounts for approximately $1\%$ only. Besides $X(3872)$, we have obtained a higher-energy state around $3957.9$ MeV with a width of $16.7$ MeV, which may be a potential candidate for the $X(3940)$. In $J^{PC}=1^{+-}$ sector, we have found two states related to the iso-scalar $\tilde{X}(3872)$ and $h_c(2P)$, respectively. Our combined study provides valuable insights into the nature of these $D{D}^{\ast }$/$D{\bar{D}}^{\ast }$ exotic states.

    hep-phSci.Bull.(2024)·59 citations
14. 14*

    On the gauge-invariance of SCET beyond leading power

    Philipp Böer🇩🇪 · Patrick Hager🇩🇪

    We point out that the gauge-invariance of the subleading Lagrangian of soft-collinear effective theory is realised in an intricate way through momentum-conservation violating contributions. Although these terms are disregarded in diagrammatic calculations, the gauge invariance of any physical transition amplitude is preserved due to the soft equations of motion. When not working with gauge-invariant building blocks, individual manifestly gauge-invariant constituent terms in the Lagrangian may give rise to gauge-dependent matrix elements starting at $\mathcal{O}({\lambda }^2)$. Implications for a gauge-invariant definition of radiative jet functions are discussed.

    hep-phJHEP(2023)·9 citations
15. 15*

    A Generic Formation Mechanism of Ultralight Dark Matter Solar Halos

    Dmitry Budker🇩🇪 · Joshua Eby🇯🇵 · Marco Gorghetto🇮🇱 · Minyuan Jiang🇮🇱 · Gilad Perez🇮🇱

    As-yet undiscovered light bosons may constitute all or part of the dark matter (DM) of our Universe, and are expected to have (weak) self-interactions. We show that the quartic self-interactions generically induce the capture of dark matter from the surrounding halo by external gravitational potentials such as those of stars, including the Sun. This leads to the subsequent formation of dark matter bound states supported by such external potentials, resembling gravitational atoms (e.g. a solar halo around our own Sun). Their growth is governed by the ratio ${\xi }_{\mathrm{foc}}\equiv {\lambda }_{\mathrm{dB}}/R_{\star }$ between the de Broglie wavelength of the incoming DM waves, ${\lambda }_{\mathrm{dB}}$, and the radius of the ground state $R_{\star }$. For ${\xi }_{\mathrm{foc}}\lesssim 1$, the gravitational atom grows to an (underdense) steady state that balances the capture of particles and the inverse (stripping) process. For ${\xi }_{\mathrm{foc}}\gtrsim 1$, a significant gravitational-focusing effect leads to exponential accumulation of mass from the galactic DM halo into the gravitational atom. For instance, a dark matter axion with mass of the order of $10^{-14}$ eV and decay constant between $10^7$ and $10^8$ GeV would form a dense halo around the Sun on a timescale comparable to the lifetime of the Solar System, leading to a local DM density at the position of the Earth $\mathcal{O}(10^4)$ times larger than that expected in the standard halo model. For attractive self-interactions, after its formation, the gravitational atom is destabilized at a large density, which leads to its collapse; this is likely to be accompanied by emission of relativistic bosons (a `Bosenova').

    hep-phastro-ph.COhep-thphysics.atom-phJCAP(2023)·82 citations
16. 16*

    A Precise Electron EDM Constraint on CP-odd Heavy-Quark Yukawas

    Joachim Brod🇺🇸 · Zachary Polonsky🇨🇭 · Emmanuel Stamou🇩🇪

    CP-odd Higgs couplings to bottom and charm quarks arise in many extensions of the standard model and are of potential interest for electroweak baryogenesis. These couplings induce a contribution to the electron EDM. The experimental limit on the latter then leads to a strong bound on the CP-odd Higgs couplings. We point out that this bound receives large QCD corrections, even though it arises from a leptonic observable. We calculate the contribution of CP-odd Higgs couplings to the bottom and charm quarks in renormalisation-group improved perturbation theory at next-to-leading order in the strong interaction, thereby reducing the uncertainty to a few percent.

    hep-phJHEP(2024)·21 citations
17. 17*

    A boosted muon collider

    Daniele Barducci🇮🇹 · Alessandro Strumia🇮🇹

    A muon collider could produce the heavier Standard Model particles with a boost, for example in resonant processes such as ${\mu }^{-}{\mu }^{+}\to h$ or ${\mu }^{-}{\mu }^{+}\to Z$. We propose machine configurations that produce the boost (asymmetric beam energies, tilted beams) and estimate how much the luminosity is reduced or perhaps enhanced. The feasibility of the proposed configurations, as well as an estimation of the beam-induced backgrounds and beam energy spread, needs to be evaluated in order to derive more solid conclusions on the physics potential of such boosted collider configurations. If achievable, the boost can provide new interesting observational opportunities. For example it can significantly enhance the sensitivity to long-lived new particles decaying in a far-away detector, such as dark higgses or sterile neutrinos produced in $h$ or $Z$ decays.

    hep-phhep-exJHEP(2023)·5 citations
18. 18*

    Superheavy Elements and Ultradense Matter

    Evan LaForge🇺🇸 · Will Price🇺🇸 · Johann Rafelski🇺🇸

    In order to characterize the mass density of superheavy elements, we solve numerically the relativistic Thomas-Fermi model of an atom. To obtain a range of mass densities for superheavy matter, this model is supplemented with an estimation of the number of electrons shared between individual atoms. Based on our computation, we expect that elements in the island of nuclear stability around $Z=164$ will populate a mass density range of $36.0-68.4$ g/cm${}^3$. We then extend our method to the study of macroscopic alpha particle nuclear matter condensate drops.

    ↳ nucl-thhep-phphysics.atom-phEur.Phys.J.Plus(2023)·1 citation
19. 19*

    Exploring the chiral and deconfinement phase transitions in a self-consistent PNJL model

    Xiaozhu Yu🇨🇳 · Liangkai Wu🇨🇳 · Lang Yu🇨🇳 · Xinyang Wang🇨🇳

    In this work, we study the chiral and deconfinement phase transitions in a two-flavor Polyakov loop extended Nambu--Jona-Lasinio (PNJL) model. And note that the self-consistent mean field approximation is employed by introducing an arbitrary parameter $\alpha$ to measure the weights of the Fierz-transformed interaction channels. By making use of this model, we systematically investigate the chiral and deconfinement phase transition lines (as well as the chiral ones in the NJL model for comparison) under different values of $\alpha$. It is found that, the increasing of $\alpha$ helps to enhance the chiral (pseudo)critical temperature at fixed chemical potential, and also to enhance the chiral (pseudo)critical chemical potential at fixed temperature. And the critical end point (CEP) vanishes when $\alpha$ becomes large enough. Besides, we find that the incorporation of Polyakov loop increases $T_{CEP}$ but does not change ${\mu }_{CEP}$ for small values of $\alpha$.

    ↳ nucl-thhep-phEPJA(2024)·2 citations
20. 20*

    A Poincaré covariant cascade method for high-energy nuclear collisions

    Yasushi Nara🇯🇵 · Asanosuke Jinno🇯🇵 · Tomoyuki Maruyama🇯🇵 · Koichi Murase🇯🇵 · Akira Ohnishi🇯🇵

    We present a Poincaré covariant cascade algorithm based on the constrained Hamiltonian dynamics in an $8N$-dimensional phase space to simulate the Boltzmann-type two-body collision term. We compare this covariant cascade algorithm with traditional $6N$-dimensional phase-space cascade algorithms. To validate the covariant cascade algorithm, we perform box calculations. We examine the frame dependence of the algorithm in a one-dimensionally expanding system as well as the compression stages of colliding two nuclei. We confirm that our covariant cascade method is reliable to simulate high-energy nuclear collisions. Furthermore, we present Lorentz-covariant equations of motion for the $N$-body system interacting via potentials, which can be efficiently solved numerically.

    ↳ nucl-thhep-phnucl-exPRC(2023)·11 citations
21. 21*

    Primordial non-Gaussianity from ultra slow-roll Galileon inflation

    Sayantan Choudhury🇮🇳 · Ahaskar Karde🇮🇳 · Sudhakar Panda🇮🇳 · M. Sami🇮🇳

    We present a detailed study of the generation of large primordial non-Gaussianities during the slow-roll (SR) to ultra-slow roll (USR) transitions in the framework of Galileon inflation. We found out that due to having sharp transitions in the USR phase, which persist with a duration of $\Delta N_{\mathrm{USR}}\sim 2$ e-folds, we are able to generate the non-Gaussianity amplitude of the order: $|f_{\mathrm{NL}}|\sim O(10^{-2})$ in the SRI, $-5<f_{\mathrm{NL}}<5$ in the USR, and $-2<f_{\mathrm{NL}}<2$ in the SRII phases. As a result, we are able to achieve a cumulative average value of $|f_{\mathrm{NL}}|\sim O(1)$. This implies that our results strictly satisfy Maldacena's no-go theorem in the squeezed limit only for SRI, while they strictly violate the same condition in both the USR and SRII phases. The non-renormalization theorem in the Galileon theory helps to support our results regarding the generation of large mass primordial black holes along with large non-Gaussianities, which we show to be dependent on the specific positions of the transition wave numbers fixed at low scales.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·58 citations
22. 22*

    Incompatibility of gravity theories with auxiliary fields with the Standard Model

    Giulia Ventagli🇬🇧 · Paolo Pani🇮🇹 · Thomas P. Sotiriou🇬🇧

    Theories of gravity with auxiliary fields are of particular interest since they are able to circumvent Lovelock's theorem while avoiding to introduce new degrees of freedom. This type of theories introduces derivatives of the stress-energy tensor in the modified Einstein equation. This peculiar structure of the field equations was shown to lead to spacetime singularities on the surface of stars. Here we focus on yet another problem afflicting gravity theories with auxiliary field. We show that such theories introduce deviations to the Standard Model unless one severely constrains the parameters of the theory, preventing them to produce significant phenomenology at large scales. We first consider the specific case of Palatini $f(\mathcal{R})$ gravity, to clarify the results previously obtained in arXiv:astro-ph/0308111. We show that the matter fields satisfy the Standard Model field equations which reduce to those predicted by General Relativity in the local frame only at tree level, whereas at higher orders in perturbation theory they are affected by corrections that percolate from the gravity sector regardless of the specific $f(\mathcal{R})$ model considered. Finally, we show that this is a more general issue affecting theories with auxiliary fields connected to the same terms responsible for the appearance of surface singularities.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2024)·2 citations
23. 23*

    Tracking the Multifield Dynamics with Cosmological Data: A Monte Carlo approach

    William Giarè🇬🇧 · Mariaveronica De Angelis🇬🇧 · Carsten van de Bruck🇬🇧 · Eleonora Di Valentino🇬🇧

    We introduce a numerical method specifically designed for investigating generic multifield models of inflation where a number of scalar fields ${\varphi }^K$ are minimally coupled to gravity and live in a field space with a non-trivial metric $G_{IJ}({\varphi }^K)$. Our algorithm consists of three main parts. Firstly, we solve the field equations through the entire inflationary period, deriving predictions for observable quantities such as the spectrum of scalar perturbations, primordial gravitational waves, and isocurvature modes. We also incorporate the transfer matrix formalism to track the behavior of adiabatic and isocurvature modes on super-horizon scales and the transfer of entropy to scalar modes after the horizon crossing. Secondly, we interface our algorithm with Boltzmann integrator codes to compute the subsequent full cosmology, including the cosmic microwave background anisotropies and polarization angular power spectra. Finally, we develop a novel sampling algorithm able to efficiently explore a large volume of the parameter space and identify a sub-region where theoretical predictions agree with observations. In this way, sampling over the initial conditions of the fields and the free parameters of the models, we enable Monte Carlo analysis of multifield scenarios. We test all the features of our approach by analyzing a specific model and deriving constraints on its free parameters. Our methodology provides a robust framework for studying multifield inflation, opening new avenues for future research in the field.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·21 citations
24. 24*

    Superstring Cosmology -- A Complementary Review

    Robert Brandenberger (McGill University)🇨🇦

    In this review, a number of approaches to superstring cosmology which make use of key features which distinguish string theory from point particle theories are discussed, with particular emphasis on emergent scenarios. One motivation for the discussion is the realization that, in order to describe the evolution of the very early universe, it is necessary to go beyond a conventional effective field theory (EFT) analysis. Some of the conceptual problems of an EFT analysis will be discussed. The review begins with a summary of the criteria for a successful early universe scenario, emphasizing that cosmic inflation is not the only scenario of early universe cosmology which is consistent with current cosmological observations. Bouncing and emergent scenarios as interesting alternatives are introduced. Some realizations of these scenarios from superstring theory are reviewed, e.g. String Gas Cosmology, the Pre-Big-Bang scenario, the Ekpyrotic model, Double Field Theory cosmology and matrix model cosmology. In light of the difficulties in obtaining cosmic inflation from string theory (at the level of EFT), and realizing that there are promising examples of alternative early universe scenarios which are derived from basic principles of superstring theory, one must entertain the possibility that the cosmology emerging from string theory will not involve an extended period of accelerated expansion.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2023)·39 citations
25. 25*

    The weak, the strong and the ugly -- A comparative analysis of interacting stepped dark radiation

    Nils Schöneberg🇪🇸 · Guillermo Franco Abellán🇳🇱 · Théo Simon🇫🇷 · Alexa Bartlett🇺🇸 · Yashvi Patel🇺🇸 · Tristan L. Smith🇺🇸

    Models which address both the Hubble and $S_8$ tensions with the same mechanism generically cause a pre-recombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a self-interacting dark radiation fluid scattering with dark matter, which has a step in its abundance around some transition redshift. In one model, the interaction is weak and with all of the dark matter whereas in the other it is strong but with only a fraction of the dark matter. The weakly interacting case is able to address both tensions simultaneously and provide a good fit to a the Planck measurements of the cosmic microwave background (CMB), the Pantheon Type Ia supernovae, and a combination of low and high redshift baryon acoustic oscillation data, whereas the strongly interacting model cannot significantly ease both tensions simultaneously. The addition of high-resolution cosmic microwave background (CMB) measurements (ACT DR4 and SPT-3G) slightly limits both model's ability to address the Hubble tension. The use of the effective field theory of large-scale structures analysis of BOSS DR12 LRG and eBOSS DR16 QSO data additionally limits their ability to address the $S_8$ tension. We explore how these models respond to these data sets in detail in order to draw general conclusions about what is required for a mechanism to address both tensions. We find that in order to fit the CMB data the time dependence of the suppression of the matter power spectrum plays a central role.

    ↳ astro-ph.COhep-phPRD(2023)·42 citations
26. 26*

    An algorithm to approximate the real trilogarithm for a real argument

    Alexander Voigt🇩🇪

    We present an algorithm to approximate the real trilogarithm for a real argument with IEEE 754-1985 double precision accuracy. The approximation is structured such that it can make use of instruction-level parallelism when executed on appropriate CPUs.

    ↳ cs.MScs.NAhep-phmath.NA1 citation

* 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.