We present a collection of explicit formulas for the minimum volume of Sasaki-Einstein 5-manifolds. The cone over these 5-manifolds is a toric Calabi-Yau 3-fold. These toric Calabi-Yau 3-folds are associated with an infinite class of $4d$ $\mathcal{N}=1$ supersymmetric gauge theories, which are realized as world volume theories of D3-branes probing the toric Calabi-Yau 3-folds. Under the $\mathrm{AdS}/\mathrm{CFT}$ correspondence, the minimum volume of the Sasaki-Einstein base is inversely proportional to the central charge of the corresponding $4d$ $\mathcal{N}=1$ superconformal field theories. The presented formulas for the minimum volume are in terms of geometric invariants of the toric Calabi-Yau 3-folds. These explicit results are derived by implementing machine learning regularization techniques that advance beyond previous applications of machine learning for determining the minimum volume. Moreover, the use of machine learning regularization allows us to present interpretable and explainable formulas for the minimum volume. Our work confirms that, even for extensive sets of toric Calabi-Yau 3-folds, the proposed formulas approximate the minimum volume with remarkable accuracy.

We develop a new regularization method for the stress-energy tensor and the two-point function of free quantum scalar fields propagating in cosmological spacetimes. We proceed by extending the adiabatic regularization scheme with the introduction of two additional mass scales. By setting them to the order of the physical scale of the studied scenario, we obtain ultraviolet-regularized quantities that do not distort the power spectra amplitude at the infrared scales amplified by the expansion of the Universe. This is not ensured by the standard adiabatic approach. We also show how our proposed subtraction terms can be interpreted as a renormalization of coupling constants in the Einstein equations. We finally illustrate our proposed regularization method in two scenarios of cosmological interest: de Sitter inflation and geometric reheating.

We present a spin-induced non-geodesic effect of Dirac wave packets in a static uniform gravitational field. Our approach is based on the Foldy-Wouthuysen transformation of Dirac equation in a curved spacetime, which predicts a gravitational spin-orbit coupling. Due to this coupling, we find that the dynamics of the free-fall Dirac wave packets with opposite spin polarization will yield the transverse splitting in the direction perpendicular to spin orientation and gravity, which is known as the gravitational spin Hall effect. Even in a static uniform gravitational field, such effect suggests that the weak equivalence principle is violated for quantum particles.

In this work, we explore the possibility that early dark energy (EDE) is dynamical in nature and study its effect on cosmological observables. We introduce a parametrization of the equation of state allowing for an equation of state $w$ differing considerably from cosmological constant (cc, $w=-1$) and vary both the initial $w_i$ as well final $w_f$ equation of state of the EDE fluid. This idea is motivated by the fact that in many models of EDE, the scalar field may have some kinetic energy when it starts to behave like EDE before the cosmic microwave background (CMB) decoupling. We find that the present data have a mild preference for non-cc early dark energy ($w_i=-0.78$) using $\mathrm{Planck}+\mathrm{BAO}+\mathrm{Pantheon}+\mathrm{S}{H}_0\mathrm{ES}$ datasets, leading to $\mathrm{\Delta }{\chi }_{\min }^2$ improvement of $-2.5$ at the expense of one more parameter. However, $w_i$ is only weakly constrained, with $w_i<-0.56$ at $1\sigma$. We argue that allowing for $w_i\ne -1$ can play a role in decreasing the ${\sigma }_8$ parameter. Yet, in practice the decrease is only $\sim 0.4\sigma$ and ${\sigma }_8$ is still larger than weak lensing measurements. We conclude that while promising, a dynamical EDE cannot resolve both $H_0$ and ${\sigma }_8$ tensions simultaneously.

Axion dark matter (DM) produces echo images of bright radio sources via stimulated decay. These images appear as a faint radio line centered at half the axion mass, with the line width set by the DM velocity dispersion. Due to the kinematics of the decay, the echo can be emitted in the direction nearly opposite to the incoming source of stimulating radiation, meaning that axions effectively behave as imperfect monochromatic mirrors. We present an all-sky analysis of axion DM-induced echo images using extragalactic radio point sources, Galactic supernova remnants (SNRs), and Galactic synchrotron radiation (GSR) as sources of stimulating radiation. The aggregate signal strength is not significantly affected by unknown properties of individual sources of stimulating radiation, which we sample from an empirical distribution to generate an ensemble of realizations for the all-sky signal template. We perform forecasts for CHIME, HERA, CHORD, HIRAX, and BURSTT, finding that they can run as competitive axion experiments simultaneously with other objectives, requiring no new hardware.

Measuring the electron diffusion coefficient is the most straightforward task in the study of gamma-ray pulsar halos. The updated measurements of the spatial morphology and spectrum of the Geminga halo by the High-Altitude Water Cherenkov (HAWC) experiment enable us to constrain parameters beyond the diffusion coefficient, including the size of the slow-diffusion zone and the electron injection spectrum from the pulsar wind nebulae (PWNe). Based on the two-zone diffusion model, we find that the slow-diffusion zone size ($r_{*}$) around Geminga is within the range of 30–70 pc. The lower boundary of this range is determined by the goodness of fit of the model to the one-dimensional morphology of the Geminga halo. The upper limit is derived from fitting the gamma-ray spectrum of the Geminga halo, along with the expectations for the power-law index of the injection spectrum based on simulations and PWNe observations, i.e., $p\gtrsim 1$. With $r_{*}$ set at its lower limit of 30 pc, we obtain the maximum $p$ permitted by the HAWC spectrum measurement, with an upper limit of 2.17 at a $3\sigma$ significance. Moreover, we find that when $r_{*}=30\mathrm{pc}$ and $p=2.17$, the predicted positron spectrum generated by Geminga at Earth coincides with the AMS-02 measurement in the 50–500 GeV range.

GstLAL is a stream-based matched-filtering search pipeline aiming at the prompt discovery of gravitational waves from compact binary coalescences such as the mergers of black holes and neutron stars. Over the past three observation runs by the LIGO, Virgo, and KAGRA Collaboration, the GstLAL search pipeline has participated in several tens of gravitational wave discoveries. The fourth observing run (O4) is set to begin in May 2023 and is expected to see the discovery of many new and interesting gravitational wave signals which will inform our understanding of astrophysics and cosmology. We describe the current configuration of the GstLAL low-latency search and show its readiness for the upcoming observation run by presenting its performance on a mock data challenge. The mock data challenge includes 40 days of LIGO Hanford, LIGO Livingston, and Virgo strain data along with an injection campaign in order to fully characterize the performance of the search. We find an improved performance in terms of detection rate and significance estimation as compared to that observed in the O3 online analysis. The improvements are attributed to several incremental advances in the likelihood ratio ranking statistic computation and the method of background estimation.

We propose to partially unify the sequential $SU(3{)}_c\times SU(3{)}_L\times U(1{)}_X$ model (with $\beta =1/\sqrt{3}$) into the flipped $SU(6)$ model with the gauge group $SU(6)\times U(1{)}_K$. Gauge anomaly cancellation can easily be satisfied. We discuss the relevant Higgs sector, the low energy 331 model spectrum, and the unification of $SU(3{)}_c$ and $SU(3{)}_L$ gauge couplings. Neutrino mass generation and successful gauge coupling unification can set lower/upper bounds on the 331 breaking scale. The partial proton decay lifetime of various channels, for example, the $p\to e^{+}{\pi }^0$ channel, in flipped $SU(6)$ GUT are discussed. We find that certain parameter region with $M_{331}\sim {10}^{15}\mathrm{GeV}$ of case II (for case with $M_{331}$ scale ${\tilde{\mathbf{H}}}_{\mathbf{3},\mathbf{8}}$ Higgs field) can predict a partial proton lifetime of order ${10}^{34}\mathrm{years}$ for $p\to e^{+}{\pi }^0$ mode, which can be tested soon by future DUNE and Hyper-Kamiokande experiments.

The model-independent theoretical upper bound on the thermal dark matter (DM) mass can be derived from the maximum inelastic DM cross section featuring the whole observed DM abundance. We deploy partial-wave unitarity of the scattering matrix to derive the maximal thermally averaged cross section for general number-changing processes $r\to 2$ (with $r\ge 2$), which may involve standard model particles or occur solely within the dark sector. The usual upper limit on the DM mass for $s$-wave annihilation is around 130 TeV (1 GeV) for $r=2$ (3) and only applies in the case of a freeze-out occurring in the standard cosmological scenario. We consider the effects of two nonstandard cosmological evolutions, characterized by low-temperature reheating: (i) a kinationlike scenario and (ii) an early matter-dominated scenario. In the first case, early freeze-out strengthens the unitarity bound to a few TeVs for weakly interacting massive particles (WIMPs); while in the second case, the WIMP DM can be as heavy as $\sim {10}^{10}\mathrm{GeV}$ due to a large entropy dilution.

We study the topological phase transitions occurring in three-dimensional (3D) multicomponent lattice Abelian Higgs (LAH) models, in which an $N$-component scalar field is minimally coupled with a noncompact Abelian gauge field, with a global $SU(N)$ symmetry. Their phase diagram presents a high-temperature Coulomb (C) phase, and two low-temperature molecular (M) and Higgs (H) phases, both characterized by the spontaneous breaking of the $SU(N)$ symmetry. The molecular-Higgs (MH) and Coulomb-Higgs (CH) transitions are topological transitions, separating a phase with gapless gauge modes and confined charges from a phase with gapped gauge modes and deconfined charged excitations. These transitions are not described by effective Landau-Ginzburg-Wilson theories due to the active role of the gauge modes. We show that the MH and CH transitions belong to different charged universality classes. The CH transitions are associated with the $N$-dependent charged fixed point of the renormalization-group (RG) flow of the 3D Abelian Higgs field theory (AHFT). On the other hand, the universality class of the MH transitions is independent of $N$ and coincides with that controlling the continuous transitions of the one-component ($N=1$) LAH model. In particular, we verify that the gauge critical behavior always corresponds to that observed in the 3D inverted $XY$ ($IXY$) model (dual to the 3D $XY$ vector model with Villain action) and that the correlations of an extended charged gauge-invariant operator (in the Lorenz gauge, this operator corresponds to the scalar field, and thus, it is local, justifying the use of the RG framework) have an $N$-independent critical universal behavior. This scenario is supported by numerical results for $N=1$, 2, 4, 10, 25. The MH critical behavior does not apparently have an interpretation in terms of the RG flow of the AHFT, as determined perturbatively close to four dimensions or with standard large-$N$ methods.

We compute gluelump masses and mass differences using SU(3) lattice gauge theory. We study states with total angular momentum up to $J=3$, parity $P=+,-$, and charge conjugation $C=+,-$. Computations on four ensembles with rather fine lattice spacings in the range from 0.040 to 0.093 fm allow continuum extrapolations of gluelump mass differences. We complement existing results on hybrid static potentials with the obtained gluelump masses, which represent the limit of vanishing quark-antiquark separation. We also discuss the conversion of lattice gluelump masses to the renormalon subtracted scheme, which is e.g. important for studies of heavy hybrid mesons in the Born-Oppenheimer approximation.

We revisit the evolution of generalized parton distributions at the leading order in the strong coupling constant ${\alpha }_s$ for all of the twist-2 quark and gluon operators. We rederive the relevant one-loop evolution kernels, expressing them in a form suitable for implementation, and check analytically that some basic properties, such as Dokshitzer-Gribov-Lipatov-Altarelli-Parisi/Efremov-Radyushkin-Brodsky-Lepage limits and polynomiality conservation, are fulfilled. We also present a number of numerical results obtained with a public implementation of the evolution in the library apfel++ and available within the partons framework.

We construct a one-dimensional dual theory that effectively describes the sector of the $(2+1)\mathrm{D}$ flat gravity phase space near a flat space cosmology saddle labeled by definite mass and angular momentum. This Schwarzian-type action describes the dynamics of the (pseudo-)Goldstone bosons of ${\mathrm{BMS}}_3$ algebra on a circle as the symmetry is spontaneously and anomalously broken. This 1D theory, living on the celestial circle, provides the first explicit construction of a celestial dual theory in $(2+1)\mathrm{D}$. We use it to calculate the semiclassical entropy of flat space cosmologies and find perfect agreement with existing literature.

We show that detector switching profiles consisting of trains of delta couplings are a useful computational tool to efficiently approximate results involving continuous switching functions, both in setups involving a single detector and multiple ones. The rapid convergence to the continuous results at all orders in perturbation theory for sufficiently regular switchings means that this tool can be used to obtain nonperturbative results for general particle detector phenomena with continuous switching functions.

The Friedmann equations of Cotton gravity provide a simple parametrization to reproduce, by tuning a single function, the Friedmann equations of several extensions of gravity, such as $f(R)$, modified Gauss-Bonnet $f(G)$, teleparallel $f(T)$, and more. It also includes the recently proposed conformal Killing gravity and mimetic gravity in Friedmann-Robertson-Walker space-times. The extensions generally have the form of a Codazzi tensor that may be associated to the dark sector. Fixing it by a suitable equation of state accomodates most of the postulated models that extend $\mathrm{\Lambda }\mathrm{CDM}$, as the Chevallier-Polarski-Lindler model.

We obtain a sample of 1192 type-I quasars with the UV-optical, radio, and x-ray waveband coverage, which combined with the data from Huang and Chang [Mon. Not. R. Astron. Soc. 515, 1358 (2022)] and other matching objects of SDSS-DR16 with FIRST, XMM-Newton, and Chandra Source Catalog, and a sample of 407 flat-spectrum radio-loud quasars of blazars from the Roma-BZCAT, which can be used to investigate their multiband luminosity correlations and measure the luminosity distances of these type-I radio-loud quasar (RLQ) samples. We check the correlation between x-ray, UV-optical, and radio luminosity for various groupings of radio-quiet quasars (RQQs) and RLQs by parametrizing x-ray luminosity as a sole function of UV-optical or radio luminosity and as a joint function of UV/optical radio luminosity, which also can be employed to determine these cosmological distances. By Bayesian information criterion, the data suggest that the x-ray luminosity of RQQs is indirectly correlative with radio luminosity because of the connection between UV-optical and radio luminosity. However for RLQs, the x-ray luminosity is directly related to radio luminosity, and the correlations between x-ray, optical/UV, and radio luminosity get stronger with the increase in the ratio of monochromatic luminosities. Furthermore, we compare the results from RLQs with different UV-optical power-law index ${\mathrm{\Gamma }}_{\mathrm{UV}}$, and find that the goodness of fit for RLQs with ${\mathrm{\Gamma }}_{\mathrm{UV}}\le 1.6$ is tentatively better. Finally, we apply a combination of type-I RLQs and Type Ia supernova (SN Ia) Pantheon to verify the nature of dark energy concerning whether or not its density deviates from the constant, and the statistical results indicate that the Lambda cold dark matter model may be in tension with type-I RLQs at $\sim 1.5\sigma$.

Time-delay interferometry (TDI) is a crucial step in the on-ground data processing pipeline of the Laser Interferometer Space Antenna (LISA), as it reduces otherwise overwhelming laser noise and allows for the detection of gravitational waves (GWs). This being said, several laser noise couplings have been identified that limit the performance of TDI. First, on-board processing, which is used to decimate the sampling rate from tens of MHz down to a few Hz, requires careful design of the antialiasing filters to mitigate folding of laser noise power into the observation band. Furthermore, the flatness of those filters is important to limit the effect of the flexing-filtering coupling. Second, the postprocessing delays applied in TDI are subject to ranging and interpolation errors. All of these effects are partially described in the literature. In this paper, we present them in a unified framework and give a more complete description of aliased laser noise and the coupling of interpolation errors. Furthermore, for the first time, we discuss the impact of laser locking on laser noise residuals in the final TDI output. To verify the validity of the analytic power spectral density (PSD) models we derive, we run numerical simulations using LISA Instrument and calculate second-generation TDI variables with PyTDI. We consider a setup with six independent lasers and with locked lasers (locking configuration N1-12). We find that laser locking indeed affects the laser noise residuals in the TDI combinations as it introduces correlations among the six lasers inducing slight modulations of the PSDs compared to the case of six independent lasers. This implies further studies on laser noise residuals should consider the various locking configurations to produce accurate results.

Utilizing the Lehmann-Symanzik-Zimmermann reduction formula, we present a new general framework for computing scattering amplitudes in quantum field theory with quantum computers in a fully nonperturbative way. In this framework, one only has to construct one-particle states of zero momentum, and no wave packets of incoming particles are needed. The framework is able to incorporate scatterings of bound states, and is ideal for scatterings involving a small number of particles. We expect this framework to have particular advantages when applied to exclusive hadron scatterings. As a proof of concept, by simulations on classical hardware, we demonstrate that in the one-flavor Gross-Neveu model, the fermion propagator, the connected fermion four-point function, and the propagator of a fermion-antifermion bound state obtained from our proposed quantum algorithm have the desired pole structure crucial to the implementation of the Lehmann-Symanzik-Zimmermann reduction formula.

We generalize a recently introduced formulation of relativistic spinful and vortical fluid to relativistic magnetohydrodynamics (MHD). We refer to it as the “spinful-vortical MHD” (SVMHD). The aim is to scrutinize the interplay between the vorticity, magnetic field, and spin, which is treated as a quantum object, in contrast to other formulations of spin hydrodynamics. To this purpose, we first perform a standard entropy current analysis up to first-order gradient expansion, $\mathcal{O}(\partial )$ as well as $\mathcal{O}(\hslash \partial )$, where $\hslash$ is the Planck constant. In contrast to alternative formulations of spin MHD, in the absence of vorticity, the zeroth-order energy-momentum tensor includes an additional magnetovorticity mixed term and reduces, as expected, to the energy-momentum tensor of MHD. We show that in the first order of gradient expansion, 36 dissipative transport coefficients appear. They satisfy certain constraints that guarantee the positive definiteness of the entropy production rate. We then modify the formulation of SVMHD by replacing the magnetic part of the thermal vorticity tensor with its electric part. Carrying out the same analysis as in the standard formulation, we show that in this case, the first-order constitutive relations consist of 11 nondissipative Hall-like coefficients, apart from 25 dissipative coefficients. This difference arises from different behavior of the electric and magnetic part of the thermal vorticity under time-reversal transformation.

We study the stability against thermal phonon fluctuations of the magnetic dual chiral density wave (MDCDW) phase, an inhomogeneous phase arising in cold, dense QCD in a magnetic field. Following a recent study that demonstrated the absence of the Landau-Peierls (LP) instability from this phase, we calculate the (threshold) temperature at which the phonon fluctuations wash out the long-range order over a range of magnetic fields and densities relevant to astrophysical applications. Using a high-order Ginzburg-Landau expansion, we find that the threshold temperature is very near the critical temperature for fields of order ${10}^{18}\mathrm{G}$ and still a sizable fraction of the critical temperature for fields of order ${10}^{17}\mathrm{G}$. Therefore, at sufficiently large magnetic fields, the long-range order of the MDCDW phase is preserved over most of the parameter space where the condensate is energetically favored; at smaller magnetic fields, the long-range order is still maintained over a considerable region of parameter space relevant to compact stars.