Mon·May 3, 2021Monday·May 3, 2021

1. 01*

   A stroll through the loop-tree duality

   Jesús Aguilera-Verdugo🇪🇸 · Félix Driencourt-Mangin🇪🇸 · Roger J. Hernández-Pinto🇲🇽 · Judith Plenter🇪🇸 · Renato Maria Prisco🇲🇽 · Selomit Ramírez-Uribe🇪🇸 · Andrés Rentería-Olivo🇪🇸 · Germán Rodrigo🇪🇸 · German Sborlini🇩🇪 · William J. Torres Bobadilla🇩🇪 · Francesco Tramontano🇮🇹

   The Loop-Tree Duality (LTD) theorem is an innovative technique to deal with multi-loop scattering amplitudes, leading to integrand-level representations over an Euclidean space. In this article, we review the last developments concerning this framework, focusing on the manifestly causal representation of multi-loop Feynman integrals and scattering amplitudes, and the definition of dual local counter-terms to cancel infrared singularities.

   hep-phhep-thSymmetry(2021)·42 citations
2. 02*

   Revisiting freeze-in dark matter from renormalizable operators

   Simone Biondini🇨🇭

   In this conference paper we summarise the findings of a recent study, where the impact of the ultra-relativistic regime on the production of a feebly interacting dark matter particle is considered. As its population accumulates over the thermal history, we inspected thoroughly the temperature window $T\gg M$, which has been previously neglected in the context of dark matter models with renormalizable operators. At high temperatures, and for the model considered in our work, the production rate of the feebly interacting particle is driven by multiple soft scatterings, as well as $2\to 2$ processes, that can give a large contribution to the dark matter energy density.

   hep-ph0 citations
3. 03*

   Analysis of the internal structure of hadrons using direct photon production

   David F. Rentería-Estrada🇲🇽 · Roger J. Hernández-Pinto🇲🇽 · German F. R. Sborlini🇩🇪

   Achieving a precise description of the internal structure of hadrons is a hard task, since there are several bottlenecks to obtain theoretical predictions starting from first principles. In order to complement the highly-accurate experiments, it is necessary to use ingenious strategies to impose constraints from the theory side. In this article, we describe how photons can be used to unveil the internal structure of hadrons. Using up-to-date PDFs and FFs, we explore how to describe NLO QCD plus LO QED corrections to hadron plus photon production at colliders.

   hep-phSymmetry(2021)·11 citations
4. 04*

   Integral representation for three-loop banana graph

   M.A. Bezuglov🇷🇺

   It has recently been shown that two-loop kite-type diagrams can be computed analytically in terms of iterated integrals with algebraic kernels. This result was obtained using a new integral representation for two-loop sunset subgraphs. In this paper, we have developed a similar representation for a three-loop banana integral in $d=2-2\epsilon$ dimensions. This answer can be generalized up to any given order in the $\epsilon$-expansion and can be calculated numerically both below and above the threshold. We also demonstrate how this result can be used to compute more complex three-loop integrals containing the three-loop banana as a subgraph.

   hep-phPRD(2021)·9 citations
5. 05*

   Heavy quark jet production near threshold

   Lin Dai🇮🇱 · Chul Kim🇰🇷 · Adam K. Leibovich🇺🇸

   In this paper, we study the fragmentation of a heavy quark into a jet near threshold, meaning that final state jet carries most of the energy of the fragmenting heavy quark. Using the heavy quark fragmentation function, we simultaneously resum large logarithms of the jet radius $R$ and $1-z$, where $z$ is the ratio of the jet energy to the initiating heavy quark energy. There are numerically significant corrections to the leading order rate due to this resummation. We also investigate the heavy quark fragmentation to a groomed jet, using the soft drop grooming algorithm as an example. In order to do so, we introduce a collinear-ultrasoft mode sensitive to the grooming region determined by the algorithm's $z_{\mathrm{cut}}$ parameter. This allows us to resum large logarithms of $z_{\mathrm{cut}}/(1-z)$, again leading to large numerical corrections near the endpoint. A nice feature of the analysis of the heavy quark fragmenting to a groomed jet is the heavy quark mass $m$ renders the algorithm infrared finite, allowing a perturbative calculation. We analyze this for $E_{J}R\sim m$ and $E_{J}R\gg m$, where $E_J$ is the jet energy. To do the latter case, we introduce an ultracollinear-soft mode, allowing us to resum large logarithms of $E_{J}R/m$. Finally, as an application we calculate the rate for $e^{+}{e}^{-}$ collisions to produce a heavy quark jet in the endpoint region, where we show that grooming effects have a sizable contribution near the endpoint.

   hep-phJHEP(2021)·17 citations
6. 06*

   Axion Dark Matter: How to see it?

   Yannis K. Semertzidis🇰🇷 · SungWoo Youn🇰🇷

   The axion is a highly motivated elementary particle which could address two fundamental questions in physics - the strong CP problem and the dark matter mystery. Experimental searches for this hypothetical particle have started to reach theoretically interesting sensitivity levels, particularly in the $\mu$eV (GHz) region. They rely on large volume solenoid magnetic fields and microwave resonators with signals read out by quantum noise limited amplifiers. Concurrently, there have been intensive experimental efforts to widen the search range by devising various techniques as well as to enhance sensitivities by implementing advanced technologies. The developments and improvements in these orthogonal approaches will enable us to explore most of the parameter space of the axion and axion-like particles within the next couple of decades, with the 1-25 GHz frequency range to be conquered well within the first decade. We review the experimental aspects of axion physics and discuss the past, present and future of the direct search programs.

   hep-phhep-exSci.Adv.(2022)·114 citations
7. 07*

   Consistent explanation for the cosmic-ray positron excess in p-wave Sommerfeld-enhanced dark matter annihilation

   Yu-Chen Ding🇨🇳 · Yu-Lin Ku🇨🇳 · Chun-Cheng Wei🇨🇳 · Yu-Feng Zhou🇨🇳

   Sommerfeld-enhanced dark matter (DM) annihilation through $s$-wave has been widely considered as a consistent explanation for both the observed cosmic-ray (CR) positron excess and the DM thermal relic density. However, as the $s$-wave Sommerfeld-enhanced annihilation cross section increases monotonically with decreasing DM velocity, severe constraints appear from the data of gamma rays from dwarf spheroidal satellite galaxies (dSphs) and the cosmic microwave background (CMB), as the relevant typical DM velocities are even lower than that in the Galactic halo. In this work, we consider Sommerfeld-enhanced $p$-wave DM annihilation where the DM annihilation cross section can be enhanced at certain velocities but eventually be highly suppressed when the DM velocities become extremely low. We calculate the velocity-dependent astrophysics factors ($J$-factors) for the Sommerfeld-enhanced $p$-wave DM annihilation for fifteen nearby dSphs. Taking the channel of DM annihilating into $4\mu$ through two light mediators as an example, we show that there are parameter regions where this mechanism can account for the CR positron excess and the DM relic density, while being compatible with the constraints from dSphs gamma rays measured by Fermi-LAT and that from the CMB measured by PLANCK.

   hep-phJCAP(2021)·12 citations
8. 08*

   Slepton and Electroweakino pair production with aNNLO+NNLL precision

   Juri Fiaschi🇬🇧 · Michael Klasen🇩🇪

   The level of experimental precision that will be achieved with LHC Run-III data and in the forthcoming High Luminosity stage calls for equally accurate theoretical predictions to compare with. Here we present updated cross section calculations for the electroweak production of SUSY particles at the LHC with aNNLO+NNLL (approximate next-to-next-to-leading-order plus next-to-next-to-leading-logarithmic) accuracy. Results are shown for slepton pair production and for electroweakinos pair production in their mostly higgsino or gaugino configuration, finding a further significant reduction of the factorisation and renormalisation scale dependence that stabilises the predictions to the permil level.

   hep-ph0 citations
9. 09*

   Strange pentaquarks and excited $\Xi$ hyperons in ${\Xi }_b^{-}\to J/\psi \Lambda K^{-}$ final states

   Marek Karliner🇮🇱 · Jonathan L. Rosner🇺🇸

   We comment on the recent evidence by the LHCb Collaboration for a structure in the $J/\psi \Lambda$ final state produced in the decay ${\Xi }_b^{-}\to J/\psi \Lambda K^{-}$, with minimal quark content $c\bar{c}uds$.

   hep-phhep-exSci.Bull.(2021)·14 citations
10. 10*

    Standard Model in Weyl conformal geometry

    D. M. Ghilencea🇷🇴

    We study the Standard Model (SM) in Weyl conformal geometry. This embedding is natural and truly minimal {\it with no new fields} required beyond the SM spectrum and Weyl geometry. The action inherits a gauged scale symmetry $D(1)$ (known as Weyl gauge symmetry) from the underlying geometry. The associated Weyl quadratic gravity undergoes spontaneous breaking of $D(1)$ by a geometric Stueckelberg mechanism in which the Weyl gauge field (${\omega }_{\mu }$) acquires mass by "absorbing" the spin-zero mode (${\varphi }_0$) of the ${\tilde{R}}^2$ term in the action. This mode also generates the Planck scale and the cosmological constant. The Einstein-Proca action of ${\omega }_{\mu }$ emerges in the broken phase. In the presence of the SM, this mechanism receives corrections (from the Higgs) and it can induce electroweak (EW) symmetry breaking. The EW scale is proportional to the vev of the Stueckelberg field (${\varphi }_0$). The Higgs field ($\sigma$) has direct couplings to the Weyl gauge field, and its mass may be protected at quantum level by the D(1) symmetry. The SM fermions can acquire couplings to ${\omega }_{\mu }$ only in the special case of a non-vanishing kinetic mixing of the gauge fields of $D(1)\times U(1{)}_Y$. If this mixing is indeed present, part of $Z$ boson mass is not due to the Higgs mechanism, but to its mixing with massive ${\omega }_{\mu }$. Precision measurements of $Z$ mass then set lower bounds on the mass of ${\omega }_{\mu }$ which can be light (few TeV). In the early Universe the Higgs field can have a {\it geometric} origin, by Weyl vector fusion, and the Stueckelberg-Higgs potential can drive inflation. The dependence of the tensor-to-scalar ratio $r$ on the spectral index $n_s$ is similar to that in Starobinsky inflation but shifted to lower $r$ by the Higgs non-minimal coupling to Weyl geometry.

    hep-phastro-ph.COgr-qchep-ex+1EPJC(2022)·83 citations
11. 11*

    High-energy cosmic neutrinos as a probe of the vector mediator scenario in light of the muon $g-2$ anomaly and Hubble tension

    Jose Alonso Carpio🇺🇸 · Kohta Murase🇺🇸 · Ian M. Shoemaker🇺🇸 · Zahra Tabrizi🇺🇸

    In light of the recent Muon $g-2$ experiment data from Fermilab, we investigate the implications of a gauged $L_{\mu }-L_{\tau }$ model for high energy neutrino telescopes. It has been suggested that a new gauge boson at the MeV scale can both account for the Muon $g-2$ data and alleviate the tension in the Hubble parameter measurements. It also strikes signals at IceCube from the predicted resonance scattering between high-energy neutrinos and the cosmic neutrino background. We revisit this model based on the latest IceCube shower data, and perform a four-parameter fit to find a preferred region. We do not find evidence for secret interactions. The best-fit points of $m_{Z^{\prime }}$ and $g_{\mu \tau }$ are $\sim 10$~MeV and $\sim 0.1$, respectively, depending on assumptions regarding the absolute neutrino masses, and the secret interaction parameter space allowed by the observed IceCube data overlaps with the regions of the parameter space that can explain the muon $g-2$ anomaly and Hubble tension as well. We demonstrate that future neutrino telescopes such as IceCube-Gen2 can probe this unique parameter space, and point out that successful measurements would infer the neutrino mass with $0.06\mathrm{eV}\lesssim \Sigma m_{\nu }\lesssim 0.3\mathrm{eV}$.

    hep-phastro-ph.COastro-ph.HEPRD(2023)·44 citations
12. 12*

    Combined SMEFT interpretation of Higgs, diboson, and top quark data from the LHC

    Jacob J. Ethier🇳🇱 · Giacomo Magni🇳🇱 · Fabio Maltoni🇧🇪 · Luca Mantani🇧🇪 · Emanuele R. Nocera🇳🇱 · Juan Rojo🇳🇱 · Emma Slade🇬🇧 · Eleni Vryonidou🇬🇧 · Cen Zhang🇨🇳

    We present a global interpretation of Higgs, diboson, and top quark production and decay measurements from the LHC in the framework of the Standard Model Effective Field Theory (SMEFT) at dimension six. We constrain simultaneously 36 independent directions in its parameter space, and compare the outcome of the global analysis with that from individual and two-parameter fits. Our results are obtained by means of state-of-the-art theoretical calculations for the SM and the EFT cross-sections, and account for both linear and quadratic corrections in the $1/{\Lambda }^2$ expansion. We demonstrate how the inclusion of NLO QCD and $\mathcal{O}\left({\Lambda }^{-4}\right)$ effects is instrumental to accurately map the posterior distributions associated to the fitted Wilson coefficients. We assess the interplay and complementarity between the top quark, Higgs, and diboson measurements, deploy a variety of statistical estimators to quantify the impact of each dataset in the parameter space, and carry out fits in BSM-inspired scenarios such as the top-philic model. Our results represent a stepping stone in the ongoing program of model-independent searches at the LHC from precision measurements, and pave the way towards yet more global SMEFT interpretations extended to other high-$p_T$ processes as well as to low-energy observables.

    hep-phhep-exJHEP(2021)·338 citations
13. 13*

    Direct photons emission rate and electric conductivity in twice anisotropic QGP holographic model with first-order phase transition

    Irina Ya. Aref'eva🇷🇺 · Alexey Ermakov🇷🇺 · Pavel Slepov🇷🇺

    The electric conductivity and direct photons emission rate are considered in the holographic theory with two types of anisotropy. The electric conductivity is derived in two different ways, and their equivalence for the twice anisotropic theory is shown. Numerical calculations of the electric conductivity were done for Einstein-dilaton-three-Maxwell holographic model [29]. The dependence of the conductivity on the temperature, the chemical potential, the external magnetic field, and the spatial anisotropy of the heavy-ions collision (HIC) is studied. The electric conductivity jumps near the first-order phase transition are observed. This effect is similar to the jumps of holographic entanglement that were studied previously.

    ↳ hep-thhep-phEPJC(2022)·25 citations
14. 14*

    Constraining self-interacting dark matter with the full dataset of PandaX-II

    Jijun Yang🇨🇳 · Abdusalam Abdukerim🇨🇳 · Wei Chen🇨🇳 · Xun Chen🇨🇳 · Yunhua Chen🇨🇳 · Chen Cheng🇨🇳 · Xiangyi Cui🇨🇳 · Yingjie Fan🇨🇳 · Deqing Fang🇨🇳 · Changbo Fu🇨🇳 · Mengting Fu🇨🇳 · Lisheng Geng🇨🇳 and 60 other authors

    Self-interacting Dark Matter (SIDM) is a leading candidate proposed to solve discrepancies between predictions of the prevailing cold dark matter theory and observations of galaxies. Many SIDM models predict the existence of a light force carrier that mediate strong dark matter self-interactions. If the mediator couples to the standard model particles, it could produce characteristic signals in dark matter direct detection experiments. We report searches for SIDM models with a light mediator using the full dataset of the PandaX-II experiment, based on a total exposure of 132 tonne-days. No significant excess over background is found, and our likelihood analysis leads to a strong upper limit on the dark matter-nucleon coupling strength. We further combine the PandaX-II constraints and those from observations of the light element abundances in the early universe, and show that direct detection and cosmological probes can provide complementary constraints on dark matter models with a light mediator.

    ↳ hep-exhep-phSCPMA(2021)·25 citations
15. 15*

    Generation of arbitrarily polarized GeV lepton beams via nonlinear Breit-Wheeler process

    Kun Xue🇨🇳 · Ren-Tong Guo🇨🇳 · Feng Wan🇨🇳 · Rashid Shaisultanov🇩🇪 · Yue-Yue Chen🇨🇳 · Zhong-Feng Xu🇨🇳 · Xue-Guang Ren🇨🇳 · Karen Z. Hatsagortsyan🇩🇪 · Christoph H. Keitel🇩🇪 · Jian-Xing Li🇨🇳

    Generation of arbitrarily spin-polarized lepton (here refer in particular to electron and positron) beams has been investigated in the single-shot interaction of high-energy polarized $\gamma$ photons with an ultraintense asymmetric laser pulse via nonlinear Breit-Wheeler (BW) pair production. We develop a fully spin-resolved semi-classical Monte Carlo method to describe the pair creation and polarization in the local constant field approximation. In nonlinear BW process the polarization of created pairs is simultaneously determined by the polarization of parent $\gamma$ photons, the polarization and asymmetry of scattering laser field, due to the spin angular momentum transfer and the asymmetric spin-dependent pair production probabilities, respectively. In considered all-optical method, dense GeV lepton beams with average polarization degree up to about $80\%$ (adjustable between the transverse and longitudinal components) can be obtained with currently achievable laser facilities, which could be used as injectors of the polarized $e^{+}{e}^{-}$ collider to search for new physics beyond the Standard Model.

    ↳ physics.plasm-phhep-phFund.Res.(2022)·14 citations
16. 16*

    First search for direct $CP$-violating asymmetry in $B^0\to K^0{\pi }^0$ decays at Belle II

    Belle II Collaboration: F. Abudinén🇮🇹 · I. Adachi🇯🇵 · R. Adak🇨🇳 · K. Adamczyk🇵🇱 · P. Ahlburg🇩🇪 · J. K. Ahn🇰🇷 · H. Aihara🇯🇵 · N. Akopov🇦🇲 · A. Aloisio🇮🇹 · F. Ameli🇮🇹 · L. Andricek🇩🇪 · N. Anh Ky🇻🇳 and 541 other authors

    We report on the first measurement of the direct $CP$-violating asymmetry ($\mathcal{A}$) in the charmless decay $B^0\to K^0{\pi }^0$ at Belle II and an updated measurement of its branching fraction ($\mathcal{B}$). We use a sample of electron-positron collisions collected in 2019 and 2020 at the ${\rm Y}(4S)$ resonance and corresponding to $62.8$ ${\text{fb}}^{-1}$ of integrated luminosity. We reconstruct and select about $50$ $B^0\to K_S^0{\pi }^0$ candidates, and we measure ${\mathcal{A}}_{K^0{\pi }^0}=-0.40_{-0.44}^{+0.46}(\text{stat})\pm 0.04(\text{syst})$ and $\mathcal{B}(B^0\to K^0{\pi }^0)=[8.5_{-1.6}^{+1.7}(\text{stat})\pm 1.2(\text{syst})]\times 10^{-6}$. This is the first measurement of $CP$ violation in $B^0\to K^0{\pi }^0$ decays reported by Belle II. The results agree with previous determinations and show a detector performance comparable with the best Belle results.

    ↳ hep-exhep-ph10 citations
17. 17*

    Centrality dependence of electroweak boson production in PbPb collisions at the LHC

    Florian Jonas (Münster Uni.+ORNL)🇩🇪 · Constantin Loizides (ORNL)🇺🇸

    Recent data on the nuclear modification of W and Z boson production measured by the ATLAS collaboration in PbPb collisions at $\sqrt{s_{\mathrm{nn}}}=5.02$ TeV show an enhancement in peripheral collisions, seemingly contradicting predictions of the Glauber model. The data were previously explained by arguing that the nucleon-nucleon cross section may be shadowed in nucleus-nucleus collisions, and hence suppressed compared to the proton-proton cross section at the same collision energy. This interpretation has quite significant consequences for the understanding of heavy-ion data, in particular in the context of the Glauber model. Instead, we provide an alternative explanation of the data by assuming that there is a mild bias present in the centrality determination of the measurement; on the size of the related systematic uncertainty. Using this assumption, we show that the data is in agreement with theoretical calculations using nuclear parton distribution functions. Finally, we speculate that the centrality dependence of the W${}^{-}$/W${}^{+}$ ratio may point to the relevance of a larger skin thickness of the Pb nucleus, which, if present, would result in a few percent larger PbPb cross section than currently accounted for in the Glauber model and may hence be the root of the centrality bias.

    ↳ nucl-exhep-phnucl-thPRC(2021)·15 citations
18. 18*

    Sharpening the Boundaries Between Flux Landscape and Swampland by Tadpole Charge

    Keiya Ishiguro🇯🇵 · Hajime Otsuka🇯🇵

    We investigate the vacuum structure of four-dimensional effective theory arising from Type IIB flux compactifications on a mirror of the rigid Calabi-Yau threefold, corresponding to a T-dual of the DeWolfe-Giryavets-Kachru-Taylor model in Type IIA flux compactifications. By analyzing the vacuum structure of this interesting corner of string landscape, it turns out that there exist perturbatively unstable de Sitter (dS) vacua in addition to supersymmetric and non-supersymmetric anti-de Sitter vacua. On the other hand, the stable dS vacua appearing in the low-energy effective action violate the tadpole cancellation condition, indicating a strong correlation between the existence of dS vacua and the flux-induced D3-brane charge (tadpole charge). We also find analytically that the tadpole charge constrained by the tadpole cancellation condition emerges in the scalar potential in a nontrivial way. Thus, the tadpole charge would restrict the existence of stable dS vacua, and this fact underlies the statement of the dS conjecture. Furthermore, our analytical and numerical results exhibit that distributions of $\mathcal{O}(1)$ parameters in expressions of several swampland conjectures peak at specific values.

    ↳ hep-thhep-phJHEP(2021)·21 citations
19. 19*

    An updated dark energy view of inflation

    Sveva Castello🇸🇪 · Stéphane Ilić🇫🇷 · Martin Kunz🇨🇭

    The present epoch of accelerated cosmic expansion is supposed to be driven by an unknown constituent called dark energy, which in the standard model takes the form of a cosmological constant, characterized by a constant equation of state w=-1. An interesting perspective over the role and nature of dark energy can be achieved by drawing a parallel with a previous epoch of accelerated expansion, inflation, which we assume to be driven by a single scalar field, the inflaton. Since the Planck satellite has constrained the value of $n_s$ away from 1, the inflaton cannot be identified with a pure cosmological constant, as is also suggested by the fact that inflation ended. Thus, it is interesting to verify whether a hypothetical observer would have been able to measure the deviation of the w of the inflaton from -1. To do so, we consider a class of single-field slow-roll inflationary models dubbed HSR{i}, where the hierarchy of Hubble slow-roll parameters is truncated at the i-th order. The models are tested through a MCMC analysis based on combinations of the latest Planck and BICEP2/Keck data sets, and the resulting chains are converted into sets of allowed evolution histories of w. HSR{1} is excluded observationally since it would predict that $n_s=1$, in contrast with the recent Planck constraints, while we find that HSR{2} would prefer w>-1, but is disfavoured by the addition of the BICEP2/Keck data. The overall best description for the data is provided by HSR{3}, which yields a 68% upper bound of 1+w<0.0014. Therefore, if the current era of accelerated expansion happens to have the same equation of state as inflation during the observable epoch, then current and upcoming cosmological observations will not be able to detect that w$\ne$-1. This provides a cautionary tale for drawing conclusions about the nature of dark energy on the basis of the non-observation of a deviation from w=-1.

    ↳ astro-ph.COhep-phPRD(2021)·7 citations
20. 20*

    Ultra-low frequency gravitational waves from cosmological and astrophysical processes

    Christopher J. Moore🇬🇧 · Alberto Vecchio🇬🇧

    Gravitational waves (GWs) at ultra-low frequencies ($\lesssim 100\mathrm{nHz}$) are key to understanding the assembly and evolution of astrophysical black hole (BH) binaries with masses $\sim 10^6-10^9{M}_{\odot }$ at low redshifts. These GWs also offer a unique window into a wide variety of cosmological processes. Pulsar timing arrays (PTAs) are beginning to measure this stochastic signal at $\sim 1-100\mathrm{nHz}$ and the combination of data from several arrays is expected to confirm a detection in the next few years. The dominant physical processes generating gravitational radiation at $\mathrm{nHz}$ frequencies are still uncertain. PTA observations alone are currently unable to distinguish a binary BH astrophysical foreground from a cosmological background due to, say, a first order phase transition at a temperature $\sim 1-100\mathrm{MeV}$ in a weakly-interacting dark sector. This letter explores the extent to which incorporating integrated bounds on the ultra-low frequency GW spectrum from any combination of cosmic microwave background, big bang nucleosynethesis or astrometric observations can help to break this degeneracy.

    ↳ astro-ph.COgr-qchep-phNature Astron.(2021)·63 citations
21. 21*

    Kalb-Ramond backgrounds in ${\alpha }^{\prime }$-complete cosmology

    Heliudson Bernardo🇨🇦 · Paul R. Chouha🇨🇦 · Guilherme Franzmann🇸🇪

    We study the matter-coupled equations of motion for cosmological NS massless fields including all ${\alpha }^{\prime }$ corrections in an O$(d,d)$ duality invariant approach, with emphasis on the Kalb-Ramond two-form field $B_{(2)}$ and its source. Solutions for the vacuum and matter case are found and the corresponding Einstein frame cosmologies are discussed. We also show that the ansatz for $B_{(2)}$ required by the duality invariant framework implies that the two-form is non-isotropic.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2021)·15 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.