We present an updated version of the teobresums-dalí effective one body (EOB) waveform model for spin-aligned binaries on noncircularized orbits. Recently computed 4 Post Newtonian (PN) (nonspinning) terms are incorporated in the waveform and radiation reaction. The model is informed by a restricted sample ($\sim 60$) of spin-aligned, quasicircular, numerical relativity (NR) simulations. In the quasicircular limit, the model displays EOB/NR maximal unfaithfulness ${\overline{\mathcal{F}}}_{\mathrm{EOBNR}}^{\max }\lesssim {10}^{-2}$ (with median $1.06\times {10}^{-3}$) (with Advanced LIGO noise and in the total mass range $10–200M_{\odot }$) for the dominant $\ell =m=2$ mode all over the 534 spin-aligned configurations available through the simulating extreme spacetime catalog of NR waveforms. Similar figures are also obtained with the 28 public eccentric simulating extreme spacetime simulations as well as good compatibility between EOB and NR scattering angles. The quasicircular limit of teobresums-dalí is highly consistent with the teobresums-giotto quasicircular model. We then systematically explore the importance of NR tuning also the radiation reaction of the system. When this is done, the median of the distribution of quasicircular ${\overline{\mathcal{F}}}_{\mathrm{EOBNR}}^{\max }$ is lowered to $3.92\times {10}^{-4}$, though balanced by a tail up to $\sim 0.1$ for large, positive spins. The same is true for the eccentric-inspiral datasets. We conclude that an improvement of the analytical description of the spin-dependent flux (and its interplay with the conservative part) is likely to be the cornerstone to lower the EOB/NR unfaithfulness below the ${10}^{-4}$ level all over the parameter space, thus grazing the current NR uncertainties as well as the expected needs for next generation of gravitational wave detector like the Einstein Telescope.

The fundamental constants at recombination can differ from their present-day values due to degeneracies in cosmological parameters, raising the possibility of yet-undiscovered physics coupled directly to the Standard Model. We study the cosmology of theories in which a new, hyperlight scalar field modulates the electron mass and fine-structure constant at early times. We find new degeneracies in cosmologies that pair early recombination with a new contribution to the matter density arising at late times, whose predictions can be simultaneously consistent with CMB and low-redshift distance measurements. Such “late dark matter” already exists in the Standard Model in the form of massive neutrinos but is necessarily realized by the scalar responsible for shifting the early-time fundamental constants. After detailing the physical effects of varying constants and hyperlight scalar fields on cosmology, we show that variations of the electron mass and fine structure constant are constrained at the percent and permille level, respectively, and a hyperlight scalar in the mass range ${10}^{-32}\mathrm{eV}\lesssim m_{\varphi }\lesssim {10}^{-28}\mathrm{eV}$ can impact what variations are allowed while composing up to a percent of the present dark matter density. We comment on the potential for models with a varying electron mass to reconcile determinations of the Hubble constant from cosmological observations and distance-ladder methods, and we show that parameter inference varies significantly between recent baryon acoustic oscillation and type Ia supernova datasets.

We study geodesics in Friedmann-Lemaître-Robertson-Walker (FLRW) cosmological models and give the full set of solutions. For azimuthal geodesics, in a closed universe, we give the angular distance traveled by a test particle moving along such a geodesic during one cycle of expansion and recollapse of the universe. We extend previous results regarding the path followed by light rays to the two-fluid case, also including a cosmological constant, as well as to massive test particles. Our work contains various new results and explicit formulas, often using special functions which naturally appear in this setting.

Our study applies the two-state formalism alongside weak measurements within a spatially homogeneous and isotropic cosmological framework, wherein Dirac spinors are intricately coupled to classical gravity. We compute the weak values of the energy-momentum tensors, the $Z$ component of spin, and the pure states. Weak measurements are a generalization and extension of the computation already made by Finster and Hainzl [A spatially homogeneous and isotropic Einstein–Dirac cosmology, J. Math. Phys. (N.Y.) 52, 042501 (2011)] in a spatially homogeneous and isotropic Einstein-Dirac cosmology. Our analysis reveals that the acceleration of the Universe expansion can be understood as an outcome of postselection, underscoring the effectiveness of weak measurement as a discerning approach for gauging cosmic acceleration.

We explore the reach of an analytical model at one loop in perturbation theory (PT) to accurately describe measurements of the galaxy power spectrum from numerical simulations in redshift space. We consider the validity range in terms of three different diagnostics: (1) the goodness of fit, (2) a figure-of-bias quantifying the error in recovering the fiducial value of a cosmological parameter, and (3) an internal consistency check of the theoretical model quantifying the running of the model parameters with the scale cut. We consider different sets of measurements corresponding to an increasing cumulative simulation volume in redshift space. For each volume, we define a median value and the associated scatter for the largest wave number where the model is valid (the $k$ reach of the model). We find, as a rather general result, that the median value of the reach decreases with the simulation volume, as expected since the smaller statistical errors provide a more stringent test for the model. This is true for all of the three definitions considered, with the one given in terms of the figure of bias providing the most stringent scale cut. More interestingly, we also find that the error associated with the $k$-reach value is quite large, with a significant probability of being as low as $0.1h{\mathrm{Mpc}}^{-1}$ (or, more generally, up to 40% smaller than the median) for all the simulation volumes considered. We explore as well the additional information on the growth rate parameter encoded in the power spectrum hexadecapole, compared to the analysis of monopole and quadrupole, as a function of simulation volume. While our analysis is, in many ways, rather simplified, we find that the gain in the determination of the growth rate is quite small in absolute value and well within the statistical error on the corresponding figure of merit.

Baryon acoustic oscillation (BAO) is one of the important standard rulers in cosmology. The results of the latest BAO measurements by Dark Energy Spectroscopic Instrument (DESI) survey have been reported. Cosmology with the varying electron mass model and the early dark energy models are regarded as interesting models to resolve the Hubble tension. We present constraints on the varying electron mass model and early dark energy models in new DESI data as well as cosmic microwave background by Planck and the conventional BAO data from 6dF, MGS, and DR12 and supernovae light curve data into analysis. Since new DESI BAO data indicate a slightly longer sound horizon $r_{d}h$ than the other BAO observations, for the varying electron mass model, the larger $H_0=69.44\pm 0.84\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ is indicated.

Many present-day axion searches attempt to probe the mixing of axions and photons, which occurs in the presence of an external magnetic field. While this process is well understood in a number of simple and idealized contexts, a strongly varying or highly inhomogeneous background can impact the efficiency and evolution of the mixing in a nontrivial manner. In an effort to develop a generalized framework for analyzing axion-photon mixing in arbitrary systems, we focus in this work on directly solving the axion-modified form of Maxwell’s equations across a simulation domain with a spatially varying background. We concentrate specifically on understanding resonantly enhanced axion-photon mixing in a highly magnetized plasma, which is a key ingredient for developing precision predictions of radio signals emanating from the magnetospheres of neutron stars. After illustrating the success and accuracy of our approach for simplified limiting cases, we compare our results with a number of analytic solutions recently derived to describe mixing in these systems. We find that our numerical method demonstrates a high level of agreement with one, but only one, of the published results. Interestingly, our method also recovers the mixing between the axion and magnetosonic-t and Alfvén modes; these modes cannot escape from the regions of dense plasma but could nontrivially alter the dynamics in certain environments. Future work will focus on extending our calculations to study resonant mixing in strongly variable backgrounds, mixing in generalized media (beyond the strong magnetic field limit), and the mixing of photons with other light bosonic fields, such as dark photons.

We present an analysis of gravitational wave (GW) predictions from five two-dimensional core collapse supernova (CCSN) simulations that varied only in the equation of state (EOS) implemented. The GW signals from these simulations are used to produce spectrograms in the absence of noise, and the emergent high-frequency feature (HFF) is found to differ quantitatively between simulations. Below 1 kHz, the HFF is well approximated by a first-order polynomial in time. The resulting slope was found to vary between 10% and 50% from model to model. Further, using real interferometric noise we investigated the current capabilities of GW detectors to resolve these differences in HFF slope for a Galactic CCSN. We find that, for distances up to 1 kpc, current detectors have the ability to resolve HFF slopes differing by 4.4%–15%. For further Galactic distances, current detectors are capable of distinguishing the upper and lower bounds of the HFF slope for groupings of our models that varied in EOS. With the higher sensitivity of future GW detectors, and with improved analysis of the HFF, our ability to resolve properties of the HFF will improve for all Galactic distances. This study shows the potential of using the HFF of CCSN produced GWs to provide insight into the physical processes occurring deep within CCSN during collapse, and in particular its potential to further constrain the EOS through GW detection.

The detection of gravitational waves (GWs) with an electromagnetic counterpart enabled the first Hubble constant $H_0$ measurement through the standard siren method. Current constraints suggest that $\sim 20–30\%$ of LIGO/Virgo/KAGRA (LVK) binary black hole (BBH) mergers might occur in active galactic nuclei (AGN) disks. The claim for a possible association of several BBH mergers with flaring AGNs suggests that cosmological analyses using BBHs and AGNs might be promising. We explore standard siren analyses through a method that takes into account the presence of background flaring AGNs, without requiring a unique host galaxy identification, and apply it to realistic GW simulations. Depending on the fraction of LVK BBHs that induce flares, we expect to constrain $H_0$ at the $\sim 6–7\%$ ($\sim 4–5\%$) precision with $\sim 2–3\mathrm{years}$ or $\sim 160–240$ events ($\sim 1\mathrm{year}$ or 500 events) of LVK at design ($\mathrm{A}+$) sensitivity, assuming that systematic BBH follow-up searches are performed. We also show that in a scenario where only $\sim 1\%$ of the BBHs induce detectable flares it is possible to achieve an $H_0$ precision from 7.5% to 15% with $\sim 240$ events. In addition, a $\sim 5–27\%$ precision is achievable with complete AGN catalogs and 1 year of LVK run, without the need of any flare identification.

We demonstrate that nongravitational interactions between dark matter and baryonic matter can affect structural properties of galaxies. Detailed galaxy simulations and analytic estimates demonstrate that dark matter which collects inside white dwarf stars and ignites type Ia supernovae can substantially alter star formation, stellar feedback, and the halo density profile through a dark matter induced baryonic feedback process, distinct from usual supernova feedback in galaxies.

The discrepancies in different measurements of the lifetime of isolated neutrons could be resolved by considering an extra neutron decay channel into dark matter, with a branching ratio of the order of $O(1\%)$. Although the decay channel into a dark fermion $\chi$ plus visible matter has already been experimentally excluded, a dark decay with either a scalar or dark photon in the final state still remains a possibility. In particular, a model with a fermion mass $m_{\chi }\approx 1\mathrm{GeV}$ and a scalar $m_{\varphi }\approx O(\mathrm{MeV})$ could provide not only the required branching ratio to explain the anomaly but also a good dark matter (DM) candidate with the right thermal abundance today. Although the interaction DM neutron will affect the formation of neutron stars, the combined effect of the dark matter self-interactions mediated by the light scalar and an effective repulsive interaction with the neutrons induced by the scalar-Higgs coupling would allow heavy enough neutron stars. Combining the constraints from neutron lifetime, dark matter abundance, neutron stars, Higgs physics, and big bang nucleosynthesis, we can restrict the light scalar mass to be in the range $2m_e<m_{\varphi }<2m_e+0.0375\mathrm{MeV}$.

We develop a theoretical framework that allows us to explore the coupled motion of neutron-superfluid vortices and proton-superconductor flux tubes in a gravitationally collapsed condensate, which describe neutron stars that form pulsars. Our framework uses the 3D Gross-Pitaevskii-Poisson-equation for neutron Cooper pairs, the real-time-Ginzburg-Landau equation for proton Cooper pairs, the Maxwell equations for the vector potential $\mathbf{A}$, and Newtonian gravity and interactions, both direct and induced by the Poisson equation, between the neutron and proton subsystems. For a pulsar we include a crust potential, characterized by an angle $\theta$, and frictional drag. By carrying out extensive direct numerical simulations of this model, we obtain a variety of interesting results. We show that a rotating proton superconductor generates a uniform London magnetic field and the field distribution around flux tubes changes. In the absence of any direct interaction between the two species, they interact through the gravitational Poisson equation. The inclusion of the current-current interaction and the complete Maxwell equations allows us to quantify the entrainment effect that leads to induced magnetization of neutron vortices. We demonstrate that, with a strong external magnetic field ${\mathbf{B}}_{\mathrm{ext}}$, proton flux tubes are anchored to the crust, whereas neutron vortices leave the condensate and lead to abrupt changes of the crust angular momentum ${\mathrm{J}}_c$. The frictional term in the dynamical equation for $\theta$ yields stick-slip dynamics that leads, in turn, to glitches in the time series of ${\mathrm{J}}_c$. By calculating various statistical properties of this time series, we demonstrate that they display self-organized criticality that has been found in observations for several pulsars. We compare our results with those of earlier explorations of pulsar-glitch statistics in Gross-Pitaevskii equation-based minimal models for pulsars.

Neutron star-white dwarf (NS-WD) binaries evolve into either ultracompact x-ray binaries undergoing stable mass transfer or direct mergers by unstable mass transfer. While much attention has been on gravitational wave (GW) emissions from NS-WD binaries with the former evolutionary pathway, this work explores GW emissions related to $r$-mode instability of the accreting NSs in NS-WD mergers particularly with WD’s mass $\gtrsim 1M_{\odot }$. Due to considerably high accretion rates, the GW emissions associated with both $r$-modes and magnetic deformation intrinsically induced by $r$-modes presented in this work are much stronger than those in NS-WD binaries categorized as intermediate-mass or low-mass x-ray binaries, rendering them interesting sources for the advanced Laser Interferometer Gravitational Wave Observatory and upcoming Einstein Telescope. Moreover, these strong GW emissions might accompany some intriguing electromagnetic emissions such as peculiar long gamma-ray bursts (LGRBs), fast blue optical transients including kilonovalike emissions associated with peculiar LGRBs, and/or fast radio bursts.

The Laser Interferometer Space Antenna (LISA) is a space-based observatory for gravitational waves currently under development. It will comprise three spacecraft that orbit the Sun, forming a nearly equilateral triangle. The vast majority of the sources contributing to the LISA measurements will be galactic binaries. Due to their large number, the LISA measurements of galactic binaries need to be simulated accurately and rapidly for various testing and processing purposes. For a rapid forward simulation, the computation of the measurements is split such that parts are performed in the time and frequency domains, respectively. We show how an inaccurate implementation of this method can lead to errors when simulating the measurements for a finite time of observation. We modify the forward simulation method accordingly and introduce a technique to further accelerate the computation. Finally, real LISA measurements will contain large noise components. These are reduced in a postprocessing step, which is commonly included in the forward simulation. This noise-reduction procedure involves delaying the LISA measurements by multiples of the time-varying LISA arm lengths. For an efficient evaluation of the delays, it is often inaccurately assumed that the LISA arm lengths are constant. We show that the time variations of the LISA arm lengths can be accounted for without significantly increasing the computational cost. The presented numerical method is suitable to be executed on GPUs. In numerical tests, we show that the LISA measurements of millions of galactic binaries can be simulated accurately within a few seconds.

We propose a novel formulation for a manifestly Lorentz-covariant spinor wave-packet basis. The traditional definition of the spinor wave packet is problematic due to its unavoidable mixing with other wave packets under Lorentz transformations. Our approach resolves this inherent mixing issue. The wave packet we develop constitutes a complete set, enabling the expansion of a free spinor field while maintaining Lorentz covariance. Additionally, we present a Lorentz-invariant expression for zero-point energy.

Quantum Fourier transformations are an essential component of many quantum algorithms, from prime factoring to quantum simulation. While the standard Abelian QFrT is well studied, important variants corresponding to non-Abelian groups of interest have seen less development. In particular, fast non-Abelian Fourier transformations are important components for both quantum simulations of field theories as well as approaches to the non-Abelian hidden subgroup problem. In this work, we present fast quantum Fourier transformations for a number of non-Abelian groups of interest for high energy physics, $\mathbb{B}\mathbb{T}$, $\mathbb{B}\mathbb{O}$, $6\mathrm{\Delta }(27)$, $\mathrm{\Delta }(54)$, and $\mathrm{\Sigma }(36\times 3)$. For each group, we derive explicit quantum circuits and estimate resource scaling for fault-tolerant implementations. Our work shows that the development of a fast Fourier transformation can substantively reduce simulation costs by an up to three orders of magnitude for the finite groups that we have investigated.

In this article, we propose the $\mathrm{\Delta }2\mathrm{HDM}\mathrm{S}$ as a combined explanation of several excesses and anomalies observed at the LHC. Especially, $t\overline{t}$ differential distributions point towards the associated production of new electroweak scale Higgs bosons decaying into bottom quarks and $W$ bosons ($>5\sigma$) with masses consistent with the diphoton excesses at $\approx 95\mathrm{GeV}$ and $\approx 151.5\mathrm{GeV}$ ($3.8\sigma$ and $4.9\sigma$, respectively). Furthermore, CMS found indications for resonant $t\overline{t}$ production at $\approx 400\mathrm{GeV}$ ($3.5\sigma$) and both ATLAS and CMS reported elevated four-top and $t\overline{t}W$ cross sections. The $\mathrm{\Delta }2\mathrm{HDM}\mathrm{S}$ is obtained by supplementing the SM Higgs ($H_2$) with a second scalar doublet ($H_1$), real scalar singlet ($S$), and a Higgs triplet with zero hypercharge ($\mathrm{\Delta }$). We fix the masses of the neutral tripletlike and the singletlike scalars by the diphoton excesses, i.e., $m_{{\mathrm{\Delta }}^0}=151.5\mathrm{GeV}$ and $m_S=95\mathrm{GeV}$, respectively. $H$, the $CP$-even component of $H_1$, is produced via gluon fusion from a top-loop and decays dominantly to $S+{\mathrm{\Delta }}^0$ whose subsequent decays to $W^{+}{W}^{-}$ and $b\overline{b}$ explain the differential $t\overline{t}$ distributions for $\sigma (pp\to H\to S{\mathrm{\Delta }}^0)\approx 5\mathrm{pb}$. Choosing the top-Yukawa of $H_1$ accordingly, the $CP$-odd Higgs boson $A$ turns out to have the right production cross section to account for the resonant $t\overline{t}$ excess at 400 GeV, while the top-associated production of $H$ and $A$ results in new physics pollution of Standard Model $t\overline{t}W$ and $t\overline{t}t\overline{t}$ cross sections, as preferred by the data.

We introduce an ingenious approach to explore cosmological implications of higher-derivative gravity theories. The key novelty lies in the characterization of the additional massive spin-0 modes constructed from Hubble derivatives as an effective density, with the corresponding pressure uniquely determined by energy conservation, while terms with no Hubble derivatives directly alter Friedmann equations. This classification of the Universe high-derivative contributions to Friedmann equations develops insight about their cosmological impacts and is essential for understanding the Universe’s evolution across energy scales. Various examples of higher-derivative gravity theories illustrate the power of this method in efficiently solving Friedmann equations and exploring new phenomena. Using cosmic microwave background and baryonic acoustic oscillations data, we apply this method to assess the observational feasibility of wall-bouncing universes, as predicted by scenarios with, e.g., certain third order modifications to general relativity. These models also provide an inflationary phase without the need to introduce extra scalar fields.

In this letter, we study the potential of boosting the atmospheric neutrino experiments sensitivity to the neutrino mass ordering (NMO) sensitivity by incorporating inelasticity measurements. We show how this observable improves the sensitivity to the NMO and the precision of other neutrino oscillation parameters relevant to atmospheric neutrinos, specifically in the IceCube-Upgrade and KM3NeT-ORCA detectors. Our results indicate that an oscillation analysis of atmospheric neutrinos, including inelasticity information, has the potential to enhance the ordering discrimination by several units of ${\chi }^2$ in the assumed scenario of five and three years of running of IceCube-Upgrade and KM3NeT-ORCA detectors, respectively.

Diffusion is a dissipative transport phenomenon ubiquitously present in nature. Its details can now be analyzed with modern effective field theory (EFT) techniques that use the closed-time-path (or Schwinger-Keldysh) formalism. We discuss the structure of the diffusive effective action appropriate for the analysis of stochastic or thermal loop effects, responsible for the so-called long-time tails, to all orders. We also elucidate and prove a number of properties of the EFT and use the theory to establish the analytic structure of the $n$-loop contributions to diffusive retarded two-point functions. Our analysis confirms a previously proposed result by Delacrétaz that used microscopic conformal field theory arguments. Then, we analyze a number of implications of these loop corrections to the dispersion relations of the diffusive mode and new, gapped modes that appear when the EFT is treated as exact. Finally, we discuss certain features of an all-loop model of diffusion that only retains a special subset of $n$-loop “banana” diagrams.