It is expected that continuum spacetime emerges via phase transition in the tensorial group field theory (TGFT) approach to quantum gravity. Recent work on the application of Landau-Ginzburg mean-field theory to progressively realistic TGFT models has demonstrated how phase transitions can be realized therein. Here, we further develop this setting and consider the causally complete Lorentzian Barrett-Crane (BC) model which includes not only spacelike but also timelike and lightlike tetrahedra as quantum geometric building blocks. In addition, we incorporate discretized scalar fields by $\mathbb{R}$-valued variables of the group fields. In this context, we analyze models with an arbitrary single interaction of simplicial and tensor-invariant type, extend it to the model with the two vertices well known from causal dynamical triangulations, and also consider a model with colored simplicial interactions. As a main result, we demonstrate for all those cases that a mean-field approximation of a phase transition toward a nontrivial condensate state can always be realized. In particular, we show that the critical behavior is entirely driven by spacelike faces which are characterized by the boost part of the Lorentz group. The latter induces an exponential suppression of fluctuations which then stabilizes the mean-field vacuum. In contrast, timelike faces do not play a role in this as they are characterized by the rotational and thus compact part of the Lorentz group. Since such a state is typically populated by a large number of TGFT quanta, our work lends further considerable support to the existence of a sensible continuum gravitational regime for causally complete TGFT models. Our results also indirectly strengthen the derivation of effective cosmological dynamics and the recently improved study of scalar cosmological perturbations within a mean-field approximation.

We elaborate on a criterion for the emergence of instability in the fundamental mode recently observed by Cheung et al., as a universal phenomenon in the context of black hole perturbations. Such instability is characterized by an exponential spiral, deviating from the quasinormal frequencies due to an insignificant perturbation moving away from the compact object. Our analysis begins with a specific case involving a truncated Pöschl-Teller potential for which we derive an explicit form of the criterion. Notably, it is shown analytically, contrary to other cases studied in the literature, that the fundamental mode is stable. These derivations are then generalized to a broader context, embracing two underlying mathematical formalisms. Specifically, the spiral is attributed to either the poles in the black hole’s reflection amplitude or the zeros in the transmission amplitude. Additionally, we revisit and then generalize a toy model in which perturbations to the effective potential are disjointed, demonstrating that such a configuration invariably leads to instability in the fundamental mode, and the resulting outward spiral always occurs in the counterclockwise direction. The derived criterion is not restricted to the fundamental mode but is generally relevant for the first few low-lying modes. We demonstrate numerically that the spiral’s period and the frequency’s relative deviation agree well with our analytical estimations.

In a previous publication, we studied the parameter space of the phenomenological minimal Supersymmetric standard model with a light neutralino thermal dark matter ($M_{{\tilde{\chi }}_1^0}\le M_h/2$) and observed that the recent results from the dark matter and collider experiments put strong constraints on this scenario. In this work, we present in detail the arguments behind the robustness of this result against scanning over the large number of parameters in phenomenological minimal Supersymmetric standard model. The Run 3 of LHC will be crucial in probing the surviving regions of the parameter space. We further investigate the impact of light staus on our parameter space and also provide benchmarks that can be interesting for Run 3 of LHC. We analyze these benchmarks at the LHC using the machine learning framework of xgboost. Finally, we also discuss the effect of nonstandard cosmology on the parameter space.

We discuss modular family symmetry in effective theories based on generic properties of bottom-up local F-theory inspired grand unified theories (GUTs) broken by fluxes, which we refer to as fluxed GUTs. We argue that the Yukawa couplings will depend on the complex structure moduli of the matter curves in such a way that they can be modular forms associated with these symmetries. To illustrate the approach, we analyze in detail a concrete local fluxed $SU(5)$ GUT with modular $S_4$ family symmetry.

The quark gluon plasma produced in heavy-ion collisions has three relevant conserved charges: baryon number ($B$), strangeness ($S$), and electric charge ($Q$). Here we derive the Israel-Stewart framework for BSQ diffusion coupled to shear and bulk viscosity and the thermodynamic derivatives needed to couple this to a BSQ equation of state. We reproduce a subset of the $\mathcal{J}$ terms in the DNMR approach (i.e., terms of order $Kn\text{−}R{e}^{-1}$) and propose a technique to derive other terms from the maximum entropy principle. Finally, we preform a stability analysis that can be used to constraint transport coefficients in BSQ hydrodynamics.

The indirect production mechanisms of doubly charmed tetraquark $T_{cc}$ through three decay channels, $\mathrm{Higgs}/Z^0\to ⟨cc{⟩}_{\overline{3}}+\overline{c}+\overline{c}\to T_{cc}^{\overline{q}\overline{q^{\prime }}}+\overline{c}+\overline{c}$ and $W^{+}\to ⟨cc{⟩}_{\overline{3}}+\overline{c}+\overline{s}\to T_{cc}^{\overline{q}\overline{q^{\prime }}}+\overline{c}+\overline{s}$, are analyzed within the framework of nonrelativistic QCD. The intermediate $⟨cc{⟩}_{\overline{3}}$ diquark cluster in color antitriplet evolves into tetraquark components via the fragmentation process by trapping two light antiquarks ($\overline{q}$ and $\overline{q^{\prime }}$) from the vacuum. After the considered doubly charmed tetraquark components are summed, including $T_{cc}^{\overline{u}\overline{u}}$, $T_{cc}^{\overline{u}\overline{d}}$, $T_{cc}^{\overline{d}\overline{d}}$, $T_{cc}^{\overline{u}\overline{s}}$, and $T_{cc}^{\overline{d}\overline{s}}$, the decay widths, branching ratios, and produced events each year for the production of $T_{cc}$ can be predicted at LHC and Circular Electron-Positron Collider (CEPC), respectively. The differential distributions and two main sources of theoretical uncertainty are also discussed. The results show that the produced events each year for $T_{cc}$ via $W^{+}$ decays is $1.80\times {10}^5$, nearly 2 orders of magnitude larger than that by Higgs decays ($1.11\times {10}^3$) and $Z^0$ decays ($4.81\times {10}^3$) at LHC. However at CEPC, the largest contribution for the production of $T_{cc}$ is through $Z^0$ decays, about $1.63\times {10}^6$. There are only $4.79\times {10}^{-1}$ and $2.03\times {10}^2$ $T_{cc}$ events produced each year at CEPC through Higgs and $W^{+}$ decay, respectively.

A comprehensive study of the $S$-wave heavy tetraquark states with identical quarks and antiquarks, specifically $QQ{\overline{Q}}^{\prime }{\overline{Q}}^{\prime }$ ($Q,Q^{\prime }=c$, $b$), $QQ\overline{s}\overline{s}/\overline{Q}\overline{Q}ss$, and $QQ\overline{q}\overline{q}/\overline{Q}\overline{Q}qq$ ($q=u$, $d$), are studied in a unified constituent quark model. This model contains the one-gluon exchange and confinement potentials. The latter is modeled as the sum of all two-body linear potentials. We employ the Gaussian expansion method to solve the full four-body Schrödinger equations, and search bound and resonant states using the complex-scaling method. We then identify 3 bound and 62 resonant states. The bound states are all $QQ\overline{q}\overline{q}$ states with the isospin and spin-parity quantum numbers $I(J^P)=0(1^{+})$: two bound $bb\overline{q}\overline{q}$ states with the binding energies, 153 MeV and 4 MeV below the $B{B}^{*}$ threshold, and a shallow $cc\overline{q}\overline{q}$ state at $-15\mathrm{MeV}$ from the $D{D}^{*}$ threshold. The deeper $bb\overline{q}\overline{q}$ bound state aligns with the lattice QCD predictions, while $cc\overline{q}\overline{q}$ bound state, still has a much larger binding energy than the recently observed $T_{cc}^{+}$ by LHCb collaboration. No bound states are identified for the $QQ{\overline{Q}}^{\prime }{\overline{Q}}^{\prime }$, $QQ\overline{s}\overline{s}$, and $QQ\overline{q}\overline{q}$ with $I=1$. Our analysis shows that the bound $QQ{\overline{Q}}^{\prime }{\overline{Q}}^{\prime }$ states are more probable with a larger mass ratio, $m_Q/m_{Q^{\prime }}$. Experimental investigation for these states is desired, which will enrich our understanding of hadron spectroscopy and probe insights into the confinement mechanisms within tetraquarks.

An extended vector meson dominance model is developed to describe electromagnetic nucleon form factors. The model includes families of the $\rho$- and $\omega$-mesons with the associated radial excitations. The free parameters of the model are determined using a global statistical analysis of experimental data on the electromagnetic nucleon form factors in space- and timelike regions of transferred momenta. The vector meson masses and widths are equal to their empirical values, while the residues of form factors at the poles corresponding to the ground states of the $\rho$- and $\omega$-mesons are consistent with the findings of both the Frazer-Fulco unitarity relations and the Bonn potential for coupling constants of the $\rho$- and $\omega$-mesons with nucleons. Theoretical constraints imposed on the model include the quark counting rules, the Okubo-Zweig-Iizuka rule, the scaling law of Sachs form factors at moderate momentum transfers, and the suppression of Sachs form factors near the nucleon–antinucleon threshold. A reasonable description of the nucleon form factors in the experimentally accessible range of transferred momenta, as well as the electric and magnetic nucleon radii and Zemach radii, is obtained.

In a four-dimensional Schwarzschild–de Sitter background, the spherically symmetric ($\ell =0$) contribution to the Hadamard two-point correlation function is computed for a massless minimally coupled scalar field in the Unruh state. Consideration is given to spacetime points located between the black hole and cosmological horizons. Previously it was found in two dimensions at late times for spatially separated points that the Hadamard function exhibits unbounded linear growth in time, with a rate of growth proportional to the sum of the black hole and cosmological surface gravities. Here it is shown numerically that this instability persists in four dimensions, but with a modification of the two-dimensional result due to scattering effects associated with the scalar field modes. An analytic approximation is derived for the growth rate in four dimensions and, in the limit that the black hole vanishes, is found to be equivalent to the rate of growth for the Hadamard function found previously for de Sitter space in cosmological coordinates.

With a high total mass and an inferred effective spin antialigned with the orbital axis at the 99.9% level, GW191109 is one of the most promising candidates for a dynamical formation origin among gravitational wave events observed so far. However, the data containing GW191109 are afflicted with terrestrial noise transients, i.e., detector glitches, generated by the scattering of laser light in both LIGO detectors. We study the implications of the glitch(es) on the inferred properties and astrophysical interpretation of GW191109. Using time- and frequency-domain analysis methods, we isolate the critical data for spin inference to 35–40 Hz and 0.1–0.04 s before the merger in LIGO Livingston, directly coincident with the glitch. Using two models of glitch behavior, one tailored to slow scattered light and one more generic, we perform joint inference of the glitch and binary parameters. When the glitch is modeled as slow scattered light, the binary parameters favor antialigned spins, in agreement with existing interpretations. When more flexible glitch modeling based on sine-Gaussian wavelets is used instead, a bimodal aligned/antialigned solution emerges. The antialigned spin mode is correlated with a weaker inferred glitch and preferred by $\sim 70:30$ compared to the aligned spin mode and a stronger inferred glitch. We conclude that if we assume that the data are only impacted by slow scattering noise, then the antialigned spin inference is robust. However, the data alone cannot validate this assumption and resolve the antialigned spin and potentially dynamical formation history of GW191109.

Astrophysical uncertainties in dark matter direct detection experiments are typically addressed by parametrizing the velocity distribution in terms of a few uncertain parameters that vary around some central values. Here we propose a method to optimize over all velocity distributions lying within a given distance measure from a central distribution. We discretize the dark matter velocity distribution as a superposition of streams and use a variety of information divergences to parametrize its uncertainties. With this, we bracket the limits on the dark matter–nucleon and dark matter–electron scattering cross sections, when the true dark matter velocity distribution deviates from the commonly assumed Maxwell-Boltzmann form. The methodology pursued is general and could be applied to other physics scenarios where a given physical observable depends on a function that is uncertain.

We study the color correlation between static quark and antiquark ($q\overline{q}$) that is accompanied by gluonic excitations in the confined phase at $T=0$ by constructing reduced density matrices $\rho$ in color space. We perform quenched lattice quantum chromodynamics (QCD) calculations with the Coulomb gauge adopting the standard Wilson gauge action, and the spatial volume is $L^3=32^3$ at $\beta =5.8$, which corresponds to the lattice spacing $a=0.14\mathrm{fm}$ and the system volume $L^3={4.5}^3{\mathrm{fm}}^3$. We evaluate the color density matrix $\rho$ of static $q\overline{q}$ pairs in 6 channels (${\mathrm{\Sigma }}_g^{+}$, ${{\mathrm{\Sigma }}_g^{+}}^{\prime }$, ${\mathrm{\Pi }}_u$, ${\mathrm{\Pi }}_u^{\prime }$, ${\mathrm{\Delta }}_g$, ${\mathrm{\Delta }}_g^{\prime }$), and investigate the interquark-distance dependence of color correlations. We find that as the interquark distance increases, the color correlation quenches because of color leak into the gluon field and finally approaches the random color configuration in the $q\overline{q}$ systems with and without gluonic excitations. For this color screening effect, we evaluate the “screening mass” to discuss its dependence on channels, the quantum number of the gluonic excitations.

In this work, we confront the geometrical scaling properties of inclusive deep inelastic scattering cross section ($e+p\to e+X$) with the scaling entropy obtained from event multiplicity. We show that these two quantities are equivalent in the kinematic range probed by H1 Collaboration data. We propose that scaling entropy associated with partonic interactions is a more efficient way to detect scaling in experimental data. We used a combined analysis of the inclusive cross section and entropy obtained from multiplicities $P(N)$ of final-state hadrons to accurately determine the value of the Pomeron intercept. The approach could provide new constraints for future hadron collider experiments and deepen our understanding of parton saturation.

We study supersymmetric Janus solutions from matter-coupled $F(4)$ gauged supergravity coupled to three vector multiplets and $SO(4)\sim SO(3)\times SO(3)$ gauge group. There are two supersymmetric ${\mathrm{AdS}}_6$ vacua preserving all supersymmetries with $SO(3)\times SO(3)$ and $SO(3{)}_{\mathrm{diag}}$ symmetries dual to $N=2$ superconformal field theories (SCFTs) in five dimensions. We consider a truncation to $SO(2{)}_{\mathrm{diag}}\subset SO(3{)}_{\mathrm{diag}}$ singlet scalars and find a number of new supersymmetric Janus solutions preserving eight supercharges. These solutions holographically describe conformal interfaces within $N=2$ five-dimensional SCFTs involving deformations by source terms and vacuum expectation values of relevant and irrelevant operators. Apart from the Janus solutions interpolating between $SO(3)\times SO(3)$ ${\mathrm{AdS}}_6$ vacua, some of the solutions have $SO(3{)}_{\mathrm{diag}}$ ${\mathrm{AdS}}_6$ vacua generated by holographic renormalization group (RG) flows from the $SO(3)\times SO(3)$ phases on both sides. We also give evidence for solutions describing RG-flow interfaces with a $SO(3)\times SO(3)$ ${\mathrm{AdS}}_6$ vacuum on one side and $SO(3{)}_{\mathrm{diag}}$ ${\mathrm{AdS}}_6$ vacuum on the other side. The solutions provide first examples of Janus solutions involving more than one ${\mathrm{AdS}}_6$ vacuum in six-dimensional gauged supergravity.

In this study, we employ a rigorously established mathematical foundation rooted in perturbation theory in general relativity, particularly within the gauge-invariant framework devised by Nakamura, we have derived perturbation equations at both first and second orders for arbitrary backgrounds in $f(R)$ theories of gravity. These equations are used in the context of cosmology, especially when dealing with first-order perturbations in $f(R)$. Within this framework, we have successfully formulated gauge-invariant linear equations for scalar, vector, and tensor perturbations. This generalized formulation not only provides a comprehensive perspective on perturbations but also outlines a systematic approach for transitioning to specific gauges. Consequently, we have obtained and analyzed specific gauges, such as the Newtonian and synchronous gauges, within this formalism, and we have subsequently compared our findings with existing results in the literature. We provide a map of implications and future work of this formulation.

We investigate the nonlinear stability of global anti–de Sitter space in the presence of multitrace deformations utilizing an Einstein-Klein-Gordon system with a top-down scalar potential. Our numerical simulations show that marginal and irrelevant deformations retain the nonlinear instability originally found by Bizoń and Rostworowski, while relevant deformations disrupt it. We show that the nonlinear impact of multitrace deformations is in one-to-one correspondence with how they affect the resonant character of the global anti–de Sitter normal mode eigenfrequency spectrum.

We investigate the stability of scalar perturbations around a magnetized stationary compact object in general relativity. The considered object is one of the simplest exact solutions of Einstein electrovacuum equations corresponding to a spheroidal body endowed with a dipole magnetic moment. It is effectively constructed by imposing a perfect reflection (mirror) boundary condition on a central region of the Gutsunaev-Manko spacetime. A time-domain analysis of the perturbations reveals a quasinormal phase followed by a power-law decaying tail. Our findings suggest that the exterior region of the magnetized compact object is stable in the entire parameter space. Moreover, the system tends to become generically more stable the stronger the magnetization of the central object is. Such findings can be useful for the qualitative understanding of more realistic astrophysical situations involving highly magnetized sources.

With the accumulation of pulsar timing data, the evidence of stochastic gravitational wave background (SGWB) in the nanohertz is becoming more and more significant. It is gradually becoming possible to study the theory of gravity with pulsar timing data. Since pulsar timing arrays (PTAs) can observe multiple pulsars at the same time, their different spatial correlation patterns caused by SGWB with various polarizations make it possible to detect gravitational-wave polarization. In this paper, we investigate alternative polarizations of the SGWB in the NANOGrav 15-year dataset (NG15). First, the frequentist optimal statistic (OS) approach is generalized to accommodate frequency-dependent overlap reduction function (ORF), enabling OS analysis for all polarizations including scalar-longitudinal (SL) mode. We perform the first OS analysis for SGWB with all the six polarizations in NG15. The scalar-transverse (ST) mode has comparable signal-to-noise ratio (SNR) as the tensor-transverse (TT) mode, while the SNRs for vector-longitudinal (VL) mode and SL mode are much lower. Furthermore, Bayesian analysis is used for comparison purposes. The conclusion is in good agreement with the OS analysis, and the median value with 68% credible interval for TT and ST modes are $\log {\mathrm{A}}_{\mathrm{TT}}=-14.69_{-1.65}^{+0.29}$ and $\log {\mathrm{A}}_{\mathrm{ST}}=-15.38_{-1.72}^{+0.70}$, respectively, while the upper limits at 95% confidence level for VL and SL modes are $\log {\mathrm{A}}_{\mathrm{VL}}<-15.10$ and $\log {\mathrm{A}}_{\mathrm{SL}}<-16.56$, respectively.

We present two analytical models of gravitational collapse toward the Schwarzschild black hole, starting from the interior of the revisited Schwarzschild solution recently reported [Phys. Rev. D 109, 104032 (2024)]. Both models satisfy some energy conditions at all times as long as the collapse is slower than some limit. While a singularity of the Schwarzschild black hole at the origin ($R_{\mu \nu \alpha \beta }{R}^{\mu \nu \alpha \beta }\sim r^{-6}$) forms immediately after the start of the collapse in one model, such a singularity never appears at finite time during the collapse (except $t\to \infty$) in the other model. The scheme used shows great potential for studying in detail the appearance of singularities in general relativity.

Black holes long-lived enough to be dark matter have temperatures below the MeV. Since Hawking evaporation is a quasithermal process, no GeV emission is predicted to be produced by black holes if they are part, or all, of the cosmological dark matter. However, black holes could be “spawned” at late times with masses that correspond to short lifetimes, and as such be significantly hotter and produce particles well in excess of the GeV. Here, we investigate whether such late-forming black holes could, at once, explain the tantalizing excesses found in the gamma radiation from the Galactic Center, in the flux of cosmic-ray antiprotons, and in the few tentative antihelium events reported by the antimatter spectrometer AMS-02. We find that late-forming black holes cannot simultaneously explain all these excesses. We additionally compute accurate predictions for the antideuteron, high-energy neutrino, and positron fluxes if this scenario is realized in nature. We find that while the neutrino and positron fluxes are too small compared to the expected background, a significant number of antideuteron events is expected both at AMS-02 and at the future General Antiparticle Spectrometer.