Once famous and a little mysterious, Alday-Gaiotto-Tachikawa (AGT) relations between Nekrasov functions and conformal blocks are now understood as the Hubbard-Stratanovich duality in the Dijkgraaf-Vafa (DV) phase of a peculiar Dotsenko-Fateev multilogarithmic matrix model. However, it largely remains a collection of somewhat technical tricks, lacking a clear and generalizable conceptual interpretation. Our new claim is that the Nekrasov functions emerge in matrix models as a straightforward implication of superintegrability, factorization of peculiar matrix model averages. Recently, we demonstrated that, in the Gaussian Hermitian model, the factorization property can be extended from averages of single characters to their bilinear combinations. In this paper, we claim that this is true also for multilogarithmic matrix models, where factorized quantities are just the point-split products of two characters. It is this enhanced superintegrability that is responsible for existence of the Nekrasov functions and the AGT relations. This property can be generalized both to multimatrix models, thus leading to AGT relations for multipoint conformal blocks, and to DV phases of other non-Gaussian models.

It has long been debated whether gravity should be quantized or not. Recently, the authors in [Sci. Rep. 6, 22777 (2016); Proc. Natl. Acad. Sci. U.S.A. 106, 3035 (2009)] discussed the inconsistency between causality and complementarity in a Gedankenexperiment involving the quantum superposition of massive/charged bodies, and Belenchia et al. [Phys. Rev. D 98, 126009 (2018); Int. J. Mod. Phys. D 28, 1943001 (2019)] resolved the inconsistency by requiring the quantum radiation and vacuum fluctuations of gravitational/electromagnetic field. Stimulated by their works, we reanalyze the consistency between the two physical properties, causality and complementarity, according to the quantum field theory. In this analysis, we consider a Gedankenexperiment inspired by [Sci. Rep. 6, 22777 (2016); Proc. Natl. Acad. Sci. U.S.A. 106, 3035 (2009); Phys. Rev. D 98, 126009 (2018); Int. J. Mod. Phys. D 28, 1943001 (2019)], in which two charged particles coupled with a photon field are in a superposition of two trajectories. First, we observe that causality is satisfied by the retarded propagation of the photon field. Next, by introducing an inequality between visibility and which-path information, we show that the quantum radiation and vacuum fluctuations of the photon field ensure complementarity. We further find that the Robertson inequality associated with the photon field leads to the consistency between causality and complementarity in our Gedankenexperiment. Finally, we mention that a similar feature appears in the quantum field of gravity.

In flat space and at finite temperature, there are two regimes of false vacuum decay in quantum field theory. At low temperature, the decay proceeds through thermally-assisted tunneling described by periodic Euclidean solutions—bounces—with nontrivial time dependence. On the other hand, at high temperatures the bounces are time independent and describe thermal jumps of the field over the potential barrier. We argue that only solutions of the second type are relevant for false vacuum decay catalyzed by a black hole in equilibrium with thermal bath. The argument applies to a wide class of spherical black holes, including $d$-dimensional anti–de Sitter/de Sitter Schwarzschild black holes and Reissner-Nordström black holes sufficiently far from criticality. It does not rely on the thin-wall approximation and applies to multifield scalar theories.

We complete the post-Newtonian (PN) prediction at the 3.5PN order for the spin contributions to the gravitational waveforms emitted by inspiraling compact binaries, in the case of quasicircular, equatorial orbits, where both spins are aligned with the orbital angular momentum. Using results from the multipolar post-Minkowskian wave generation formalism, we extend previous works that derived the dynamics and gravitational-wave energy flux and phasing, by computing the full waveform decomposed in spin-weighted spherical harmonics. This new calculation requires the computation of multipolar moments of higher multipolar order, new quadratic-in-spin contributions to the hereditary tail terms entering at the 3.5PN order, as well as other nonlinear interactions between moments. When specialized to the test-mass limit, our results are equivalent to those obtained in the literature for the waveform emitted by a test-mass in equatorial, circular orbits around a Kerr black hole. We also compute the factorized modes for use in effective-one-body waveform models, correcting the 2.5PN nonspinning and 3PN quadratic-in-spin terms in the (2,1) mode used in current models.

The detection of gravitational waves (GWs) has opened a new window to test the theory of gravity in the strong field regime. In general relativity (GR), GW can only possess two tensor polarization modes, which are known as the $+$ and $\times$ modes. However, vector and scalar modes can exist in some modified theories of gravity, and we can test the gravitational theories by probing these extra polarization modes. As a space-borne GW detector, TianQin will be launched in the 2030s, and it is expected to observe plenty of GW signals, including those from nearly ten thousand double white dwarfs (DWDs) in our galaxy. This offers an excellent chance for testing the existence of extra polarization modes. In this article, we analyze the capability of detecting the extra polarization modes with DWDs. For the extra modes, we consider both the leading order dipole radiation and the sub-leading quadrupole radiation. We find that the capability of TianQin has very strong dependency on the source orientation. We also analyze all the verification binaries with determined position and frequency, and find that ZTF J1539 can give the best constraint on the extra polarization modes. We have also considered the case of TianQin twin constellation, and the joint observation with LISA.

A general property of universes without initial singularity is investigated based on the singularity theorem, assuming the null convergence condition and the global hyperbolicity. As a direct consequence of the singularity theorem, the universal covering of a Cauchy surface of a nonsingular universe with a past trapped surface must have the topology of $S^3$. In addition, we find that the affine size of a nonsingular universe, defined through the affine length of null geodesics, is bounded above. In the case where a part of the nonsingular spacetime is described by Friedmann-Lemaître-Robertson-Walker spacetime, we find that this upper bound can be understood as the affine size of the corresponding closed de Sitter universe. We also evaluate the upper bound of the affine size of our Universe based on the trapped surface confirmed by recent observations of baryon acoustic oscillations, assuming that our Universe has no initial singularity.

A new way is proposed to cancel the cosmological constant. The proposal involves the metric determinant acting as a type of self-adjusting $q$-field without need of a fine-tuned chemical potential. Since the determinant of the metric now plays a role in the physics, the allowed coordinate transformations are restricted to those with unit Jacobian. This approach to the cosmological constant problem is, therefore, similar to the unimodular-gravity approach of the previous literature. The resulting cosmology has been studied and the obtained results show the natural cancellation of an initial cosmological constant if quantum-dissipative effects are included.

We study the nonequilibrium dynamics of a pseudoscalar axionlike particle (ALP) weakly coupled to degrees of freedom in thermal equilibrium by obtaining its reduced density matrix. Its time evolution is determined by the in-in effective action which we obtain to leading order in the ALP coupling but to all orders in the couplings of the bath to other fields within or beyond the standard model. The effective equation of motion for the ALP is a Langevin equation with noise and friction kernels obeying the fluctuation dissipation relation. A “misaligned” initial condition yields damped coherent oscillations, however, the ALP population increases towards thermalization with the bath. As a result, the energy density features a mixture of a cold component from misalignment and a hot component from thermalization with proportions that vary in time $(\text{cold})e^{-\mathrm{\Gamma }t}+(\text{hot})(1-e^{-\mathrm{\Gamma }t})$, providing a scenario wherein the “warmth” of the dark matter evolves in time from colder to hotter. As a specific example we consider the ALP-photon coupling $ga\overrightarrow{E}·\overrightarrow{B}$ to lowest order, valid from recombination onwards. For $T\gg m_a$ the long-wavelength relaxation rate is substantially enhanced ${\mathrm{\Gamma }}_T=\frac{g^2{m}_a^{2}T}{16\pi }$. The ultraviolet divergences of the ALP self-energy require higher-order derivative terms in the effective action. We find that at high temperature, the finite-temperature effective mass of the ALP is $m_a^2(T)=m_a^2(0)[1-(T/T_c{)}^4]$, with $T_c\propto \sqrt{m_a(0)/g}$, suggesting the possibility of an inverted phase transition, which when combined with higher derivatives may possibly indicate exotic new phases. We discuss possible cosmological consequences on structure formation, the effective number of relativistic species and birefringence of the cosmic microwave background.

Measuring core-collapse supernova neutrinos, both from individual supernovae within the Milky Way and from past core collapses throughout the Universe (the diffuse supernova neutrino background, or DSNB), is one of the main goals of current and next generation neutrino experiments. Detecting the heavy-lepton flavor (muon and tau types, collectively ${\nu }_x$) component of the flux is particularly challenging due to small statistics and large backgrounds. While the next galactic neutrino burst will be observed in a plethora of neutrino channels, allowing us to measure a small number of ${\nu }_x$ events, only upper limits are anticipated for the diffuse ${\nu }_x$ flux even after decades of data taking with conventional detectors. However, paleo detectors could measure the time-integrated flux of neutrinos from galactic core-collapse supernovae via flavor-blind neutral current interactions. In this work, we show how combining a measurement of the average galactic core-collapse supernova flux with paleo detectors and measurements of the DSNB electron-type neutrino fluxes with the next-generation water Cherenkov detector Hyper-Kamiokande and the liquid noble gas detector DUNE will allow to determine the mean supernova ${\nu }_x$ flux parameters with precision of order ten percent. Realizing this potential requires both the cosmic supernova rate out to $z\sim 1$ and the integrated Galactic supernova rate over the last $\sim 1\mathrm{Gyr}$ to be established at the $\sim 10\%$ level.

The application of deep learning to the detection of gravitational wave (GW) signals has attracted much attention in recent years, and nearly all of the existing deep learning-based GW detection algorithms are based on the convolutional neural network (CNN), which can be used to identify the GW merger moment and produce responding triggers. However, current CNN-based models are not best optimized tools in modeling the causal logic of sequential data in the time dimension to incorporate the information of the inspiral, merger and ringdown phases of the GW waveform. To address this issue we propose a deep learning model designed based on the bidirectional gated recurrent unit (BiGRU), a variant of the recurrent neural network (RNN) that is sensitive to the sequential logic of GW data. We train the neural network and implement the GW detection task by using the data obtained during the first, second and third observation runs (O1/O2/O3) of the LIGO-VIGRO scientific collaboration. We find that our BiGRU model achieves a false alarm probability (FAP) of $4.88\times {10}^{-4}$ (corresponding false alarm rate is about 1 per 18.2 hours) and maintains a detection ratio of about 89.6%. We also construct a model ensemble containing two independently trained BiGRU models and find it does not trigger any false alarm events on our testing dataset. Meanwhile, our BiGRU model not only recovers all the reported GW events of O1-O2 runs, including the unique (as of today) confident (with observed electromagnetic counterparts) GW event originating from a binary neutron star (BNS) merger (GW170817), but also achieves a detection ratio of about 80% of the O3 run. By calculating and comparing the receiver operator characteristic (ROC) curves we demonstrate the superiority of the BiGRU model over traditional CNN-based models, and show that the BiGRU model, being optimized to deal with GW waveform that sequentially contains the inspiral, merger and ringdown phases, is a potentially powerful tool to study the GW data in the future.

Motivated by a possible interplay between the mechanism of dynamical symmetry breaking and the seesaw mechanism for generating fermion masses, we present a scale-invariant model that extends the gauge symmetry of the Standard Model electroweak sector to ${\mathrm{SU}(3)}_L\otimes U(1{)}_X\otimes U(1{)}_N$, with a built-in $B-L$ symmetry. The model is based on the symmetry structure of the known 3-3-1 models and, thus, it relates the number of the three observed fermion generations with the cancellation of gauge anomalies. Symmetry breaking is triggered via the Coleman-Weinberg mechanism, taking into account a minimal set of scalar field multiplets. We establish the stability conditions for the tree-level scalar potential imposing the copositivity criteria and use the method of Gildener-Weinberg for computing the one-loop effective potential when one has multiple scalar fields. With the addition of vectorial fermions, getting their mass mainly through the vacuum expectation value of scalar singlets at ${10}^3\mathrm{TeV}$, the $B-L$ symmetry leads to textures for the fermion mass matrices, allowing seesaw mechanisms for neutrinos and quarks to take place. In particular, these mechanisms could partly explain the mass hierarchies of the quarks. Once the breakdown of the ${\mathrm{SU}(3)}_L$ symmetry is supposed to occur around 10 TeV, the model also predicts new particles with TeV-scale masses, such as a neutral scalar $H_1$, a charged scalar $H^{\pm }$, and the gauge bosons $Z^{\prime }$, $W^{\prime \pm }$, and $Y^0$, that could be searched with the high-luminosity LHC.

We study the invisible Majorana fermions of $\chi$ in bottomed baryon decays with flavor-changing neutral currents based on the model-independent effective Lagrangian between the quarks and invisible particles. From the bounds of the coupling constants extracted from the experiments, we examine the decay branching ratios of ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }\chi \chi$, ${\mathrm{\Xi }}_b^{0(-)}\to {\mathrm{\Xi }}^{0(-)}\chi \chi$, ${\mathrm{\Lambda }}_b\to n\chi \chi$, ${\mathrm{\Xi }}_b^{-}\to {\mathrm{\Sigma }}^{-}\chi \chi$, ${\mathrm{\Xi }}_b^0\to {\mathrm{\Sigma }}^0\chi \chi$, and ${\mathrm{\Xi }}_b^0\to \mathrm{\Lambda }\chi \chi$, which can be as large as 6.3, 9.2, 5.7, 5.8, 2.7, and $1.0\times {10}^{-5}$ for $m_{\chi }=2\mathrm{GeV}$, respectively. Some of these decays are accessible to the future experimental searches, such as Belle II.

Inspired by Lie algebra expansion, we consider an extension of the algebra introduced in A. Fontanella and S. J. van Tongeren [Coset space actions for nonrelativistic strings, J. High Energy Phys. 06 (2022) 80.] for the nonrelativistic string coset action in ${\mathrm{AdS}}_5\times {\mathrm{S}}^5$. We show that the extended algebra admits a nondegenerate inner product which is adjoint invariant under the full extended algebra. Furthermore, we provide a finite-dimensional representation of the extended algebra.

The three-dimensional correlation function offers an effective way to summarize the correlation of the large-scale structure even for imaging galaxy surveys. We have applied the projected three-dimensional correlation function, ${\xi }_{\mathrm{p}}$ to measure the baryonic acoustic oscillations (BAO) scale on the first-three years Dark Energy Survey data. The sample consists of about 7 million galaxies in the redshift range $0.6<z_{\mathrm{p}}<1.1$ over a footprint of $4108{\mathrm{deg}}^2$. Our theory modeling includes the impact of realistic true redshift distributions beyond Gaussian photo-$z$ approximation. ${\xi }_{\mathrm{p}}$ is obtained by projecting the three-dimensional correlation to the transverse direction. To increase the signal-to-noise of the measurements, we have considered a Gaussian stacking window function in place of the commonly used top-hat. ${\xi }_{\mathrm{p}}$ is sensitive to $D_{\mathrm{M}}(z_{\mathrm{eff}})/r_{\mathrm{s}}$, the ratio between the comoving angular diameter distance and the sound horizon. Using the full sample, $D_{\mathrm{M}}(z_{\mathrm{eff}})/r_{\mathrm{s}}$ is constrained to be $19.00\pm 0.67$ (top-hat) and $19.15\pm 0.58$ (Gaussian) at $z_{\mathrm{eff}}=0.835$. The constraint is weaker than the angular correlation $w$ constraint ($18.84\pm 0.50$), and we trace this to the fact that the BAO signals are heterogeneous across redshift. While ${\xi }_{\mathrm{p}}$ responds to the heterogeneous signals by enlarging the error bar, $w$ can still give a tight bound on $D_{\mathrm{M}}/r_{\mathrm{s}}$ in this case. When a homogeneous BAO-signal subsample in the range $0.7<z_{\mathrm{p}}<1.0$ ($z_{\mathrm{eff}}=0.845$) is considered, ${\xi }_{\mathrm{p}}$ yields $19.80\pm 0.67$ (top-hat) and $19.84\pm 0.53$ (Gaussian). The latter is mildly stronger than the $w$ constraint ($19.86\pm 0.55$). We find that the ${\xi }_{\mathrm{p}}$ results are more sensitive to photo-$z$ errors than $w$ because ${\xi }_{\mathrm{p}}$ keeps the three-dimensional clustering information causing it to be more prone to photo-$z$ noise. The Gaussian window gives more robust results than the top-hat as the former is designed to suppress the low signal modes. ${\xi }_{\mathrm{p}}$ and the angular statistics such as $w$ have their own pros and cons, and they serve an important crosscheck with each other.

We investigate the 5.49 MeV solar axions flux produced in the p(d,He3)a reaction and analyze the potential to detect it with the forthcoming large underground neutrino oscillation experiment Jiangmen Underground Neutrino Observatory (JUNO). The JUNO detector could reveal axions through various processes such as Compton and inverse Primakoff conversion, as well as through their decay into two photons or electron-positron pairs inside the detector. We perform a detailed numerical analysis in order to forecast the sensitivity on different combinations of the axion-electron ($g_{ae}$), axion-photon ($g_{a\gamma }$), and isovector axion-nucleon ($g_{3aN}$) couplings, using the expected JUNO data for different benchmark values of axion mass in a model-independent way. We find that JUNO would improve by approximately one order of magnitude current bounds by Borexino and it has the best sensitivity among neutrino experiments.

We construct a primitive gate set for the digital quantum simulation of the binary tetrahedral ($\mathbb{BT}$) group on two quantum architectures. This non-Abelian discrete group serves as a crude approximation to $SU(2)$ lattice gauge theory while requiring five qubits or one quicosotetrit per gauge link. The necessary basic primitives are the inversion gate, the group multiplication gate, the trace gate, and the $\mathbb{BT}$ Fourier transform over $\mathbb{BT}$. We experimentally benchmark the inversion and trace gates on ibm_nairobi, with estimated fidelities between 14%–55%, depending on the input state.

The sensitivity of the rare decays ${\eta }^{(\prime )}\to {\pi }^0\gamma \gamma$ and ${\eta }^{\prime }\to \eta \gamma \gamma$ to signatures of a leptophobic $B$ boson in the MeV–GeV mass range is analyzed in this work. By adding an explicit $B$-boson resonance exchange, $\eta \to B\gamma \to {\pi }^0\gamma \gamma$, to the Standard Model contributions from vector and scalar meson exchanges, and employing experimental data for the associated branching ratios, it allows us to improve the current constraints on the $B$-boson mass $m_B$ and coupling to Standard Model particles ${\alpha }_B$. From these constraints and the analysis of the available experimental $\gamma \gamma$ invariant mass distribution, we show that a $B$-boson signature in the resonant mass range $m_{{\pi }^0}\lesssim m_B\lesssim m_{\eta }$ is strongly suppressed and would be very difficult to experimentally identify, assuming that the leptophobic $B$ boson only decays to Standard Model particles. In contrast, the limits outside this mass window are less stringent and the corresponding $t$- and $u$-channel signatures may still be observable in the data, as it occurs with the nonresonant Standard Model $\rho$, $\omega$ and $\varphi$ meson exchanges. In addition, we make use of experimental data from the ${\eta }^{\prime }\to {\pi }^0\gamma \gamma$ and ${\eta }^{\prime }\to \eta \gamma \gamma$ decays to explore larger $B$-boson masses. Our results are relevant for the $B$-boson search programs at existing and forthcoming light-meson facilities, such as KLOE(-II) and Jefferson Lab Eta Factory experiments.

In the article, we study single and pair $J/\psi$ hadroproduction in the improved color evaporation model via the parton Reggeization approach. The last one is based on the $k_T$ factorization of hard processes in multi-Regge kinematics, the Kimber-Martin-Ryskin-Watt model for unintegrated parton distribution functions, and the effective field theory of Reggezied gluons and quarks, suggested by L.N. Lipatov. We compare contributions from the single and double parton scattering mechanisms in the pair $J/\psi$ production. The numerical calculations are realized using the Monte-Carlo event generator KaTie.

In the context of linear $f(\mathcal{R},T)=\mathcal{R}+\chi T$ gravity, where $\mathcal{R}$ is the Ricci scalar, $T$ is the trace of the energy-momentum tensor, and $\chi$ is a dimensionless parameter, we have obtained exact analytical and numerical solutions for isotropic perfect-fluid spheres in hydrostatic equilibrium. Our solutions correspond to two-parametric extensions of the Tolman III (T-III) and Tolman VII (T-VII) models, in terms of the compactness $\beta$ and $\chi$. By requiring configurations that exhibit monotonically decreasing radial profiles for both the energy density and pressure, compliance with the energy conditions, as well as subluminal speed of sound, we have constrained the parametric space of our solutions. We have also obtained analytically a parametric deformation of the T-VII solution that continuously interpolates between the T-III and T-VII models for any $\chi$, and in the appropriate limits, provides an analytic approximation for the uniform density configuration in linear $f(\mathcal{R},T)$ gravity. Finally, by integrating numerically the TOV equations, we have obtained a numerical solution for the uniform-density configuration and subsequently, using the mass-radius relations, we have obtained the maximum mass that can be supported by such configurations. We have found that in the appropriate parametric regime our solution is in very good agreement with the observational bounds for the masses and radii of neutron stars.