Within the basis light-front quantization framework, we systematically investigate the subleading-twist (twist-3) generalized parton distributions (GPDs) of the proton’s valence quarks beyond the Wandzura-Wilczek (WW) approximation. The twist-3 GPDs are not independent; through the equations of motion they decompose into a nongenuine contribution and a genuine twist-3 term. The latter encodes quark–quark–gluon correlations and involves interference between the light-front Fock sectors $|qqq⟩$ and $|qqqg⟩$, which are typically neglected in the WW approximation. Using light-front wave functions obtained from diagonalizing the proton light-front Hamiltonian for its $|qqq⟩$ and $|qqqg⟩$ Fock components, we compute these GPDs via their overlap representations. To further explore their physical implications, we also evaluate several twist-3–related quantities, including the quark orbital angular momentum, the total quark spin contribution, and the quark spin-orbit correlation. Our results provide new nonperturbative input on higher-twist dynamics particularly multiparton interference effects relevant for future measurements at the EicC and the EIC.

Recent evidence suggests that, at small Bjorken $x$, QCD evolution drives the proton into a state of maximal entanglement. If the evolution kernel is assumed to be conformally invariant—as is the case for the Balitsky-Fadin-Kuraev-Lipatov equation—we can describe it by a conformal field theory. Moreover, the central charge $c$ of the corresponding conformal field theory emerges as the key parameter governing the $x$ dependence of both the entanglement entropy and the structure function. Here we apply the exact Bethe ansatz methods to the quantum spin chain dual to Lipatov’s high energy effective action to extract the central charge of the theory, and find that $c=1$. This implies the $\sim x^{-1/3}$ small $x$ behavior for the structure function—the prediction that can be tested at the forthcoming Electron-Ion Collider.

The photon is arguably the most universally important particle across all fields of physics. Despite its status as a fundamental particle, at high energies the photon can be seen as a hadronic source of partons. The partonic content of the photon is very poorly constrained compared to that of the proton, with uncertainties in the photon parton distribution functions typically 1 or 2 orders of magnitude larger than their proton counterparts, despite the fact that its source, the $\gamma \to q\overline{q}$ splitting, is perturbatively calculable. The high luminosity, excellent particle identification, and far-backward electron tagging capabilities of the Electron-Ion Collider (EIC) make it an ideal environment for studying photon parton distribution functions. Similar to the $p+p$ or $\pi +p$ systems, photoproduction at the EIC can be thought of as two parton distributions colliding. One of the most powerful processes in such collisions is production of lepton pairs, i.e. $h+p\to l^{+}{l}^{-}+X$, known as the Drell-Yan process. This process has the ability to access for the first time the transverse-momentum-dependent parton distributions of the photon. The transversely polarized proton beam of the EIC additionally provides a possible means of accessing the transversity distribution of the proton without relying on fragmentation functions.

We discuss the ultraviolet fixed point of asymptotically safe dilaton quantum gravity. It differs from the Reuter fixed point by the dependence of the Planck mass on a scalar field. The gauge invariant functional flow equation in the most general approximation with up to two derivatives strengthens the argument for the existence of this fixed point. The quantum effective action obtained from the scaling solution for dilaton quantum gravity can describe inflation for early cosmology and dynamical dark energy for late cosmology.

Fractons are exotic quasiparticles whose mobility in space is restricted by symmetries. In potential real-world realizations, fractons are likely lodged to a physical material rather than absolute space. Motivated by this, we propose and explore a new symmetry principle that restricts the motion of fractons relative to a physical solid. Unlike models with restricted mobility in absolute space, these fractonic solids admit gauge-invariant momentum density, are compatible with boost symmetry, and can consistently be coupled to gravity. We also propose a holographic model for fractonic solids.

The quasinormal modes (QNMs) of a rotating quantum corrected black hole (RQCBH) are studied by employing the hyperboloidal framework for the scalar perturbation. This framework is used to cast the QNM spectra problem into a two-dimensional eigenvalue problem, then the spectra are calculated by imposing the two-dimensional pseudospectral method. Based on the resulting scalar spectra, a parameter estimation pipeline for this RQCBH model with gravitational wave data is constructed by using pyring in the ringdown phase. We use informative priors in our inference that incorporates the mass and spin distributions predicted by the inspiral-merger phase as the prior distributions for the ringdown analysis. Notably, since the waveform model beyond the Kerr black hole in pyring is designed for the tensor perturbation, the inferred posterior distributions should be interpreted as a methodological investigation rather than as physical constraints from observations. The methodological results show that the use of informative priors consistently yields a tighter posterior on the quantum correction parameter compared to analyses without such priors, and the spin inferred from the RQCBH model begins to be significant and differs from that of the Kerr model. This opens a promising avenue for testing quantum-gravity-induced deviations using gravitational-wave spectroscopy.

We scrutinize properties of electrical charges bounded to visible and dark matter sectors, in the vicinity of a magnetic poles of both sectors. It turns out that the considered system has an angular momentum despite the charges are at rest. On the other hand, investigation the behavior of electric charges of visible and hidden sectors held at rest outside a magnetically charged black hole, discloses that even if the electric charge are regarded as perturbations on a spherically symmetric magnetic static black hole in dark photon theory, at large distances it looks like a stationary axisymmetric magnetically charged black hole.

We examine the joint effects of relativistic accretion and memory-burdened evaporation on the evolution of primordial black holes (PBHs). The memory burden effect, which delays the evaporation by inducing a backreaction and making the evaporation rate scale as an inverse power law of the PBH entropy, opens up a new window that allows PBHs with $M\lesssim {10}^{15}\mathrm{g}$ to survive until the present epoch. Meanwhile, accretion increases the mass of PBHs, thereby enhancing their chances of survival for a given initial mass. We consider two main scenarios: one where PBHs evaporate completely before big bang nucleosynthesis, and another where PBHs persist until today. In the case of evaporation, we analyze the emission of dark matter (DM) and dark radiation (DR) during the process of evaporation. Conversely, in the other case, the surviving PBHs themselves can contribute as DM. We further investigate how relativistic and nonrelativistic accretion, together with memory-burdened evaporation, impact the parameter space of the emitted DM, the abundance of stable PBHs as DM, and the contribution of DR to the effective number of relativistic degrees of freedom, $\mathrm{\Delta }{N}_{\mathrm{eff}}$.

The existence of a dark baryon that mixes with the neutron leads to the possibility of neutron decay into a dark sector. Such dark decays have been studied as possibly relevant for the neutron decay anomaly and for their potential impacts on neutron stars. The most popular formulation is a dark sector consisting of a dark baryon $\chi$ and a dark scalar $\varphi$, where a neutron in vacuum decays 1% or less of the time via the channel $n\to \chi +\varphi$. In this work, we consider the effect of this additional neutron decay channel on transport in neutron star mergers. We find that the neutron dark decay rate in medium is quite slow, and thus the dark baryons modify the dense matter equation of state in a way that decreases the Urca bulk viscosity by, at most, a factor of 2–3. However, if the neutron dark decay was to occur more rapidly, then the bulk viscosity at merger temperatures of tens of MeV would be strongly enhanced, potentially rapidly damping oscillations in merger environments and therefore providing a signature of slowly equilibrating matter in the merger.

Higgsinos can be the lightest supersymmetric particles, allowing for either a full or partial dark matter interpretation, with the correct thermal freeze-out abundance obtained for masses near 1.1 TeV. Dark matter direct detection experimental results, now rapidly approaching the neutrino fog, imposes increasingly stringent requirements on Higgsino purity. We begin by summarizing the purity constraints implied by the current strong limits from the LUX-ZEPLIN experiment in 2024, presenting them as lower bounds on gaugino masses in scenarios with decoupled sfermions and heavy Higgs bosons. We further quantify how these constraints will evolve as direct detection approaches various neutrino fog discovery and exclusion definitions and future exclusion projections. Finally, given that nearly pure Higgsinos remain notoriously challenging to probe directly at colliders, we explore complementary signatures in which Higgsinos are produced from the decays of heavier superpartners, where additional leptons and jets can be used for triggering. In particular, we advocate for searches of stop and wino pairs decaying directly to Higgsinos as a promising means to probe Higgsino dark matter well into the neutrino fog era.

We propose a new and simple method for determining the renormalized quark masses from lattice simulations. Renormalized quark masses are an important input to many phenomenological applications, including searching and modeling physics beyond the Standard Model. The nonperturbative renormalization is performed using gradient flow combined with the short-flow-time expansion that is improved by renormalization group (RG) running to match to the $\overline{\mathrm{MS}}$ scheme. Implementing the RG running perturbatively, we demonstrate this method works reliably at least up to the charm-quark mass and exhibits an easily attainable “windowing condition.” Using RBC/UKQCD’s ($2+1$)-flavor Shamir domain-wall fermion ensembles with Iwasaki gauge action, we find $m_s^{\overline{\mathrm{MS}}}(\mu =2\mathrm{GeV})=89(3)\mathrm{MeV}$ and $m_c^{\overline{\mathrm{MS}}}(\mu =3\mathrm{GeV})=972(16)\mathrm{MeV}$. These results predict the scale-independent ratio $m_c/m_s=12.1(4)$. Generalization to other observables is possible, providing an efficient approach to determine nonperturbatively renormalized fermionic observables like form factors or bag parameters from lattice simulations.

We perform a stability analysis of the homogeneous ground state of nuclear matter against inhomogeneous perturbations of the pion condensate. In $\beta$ equilibrium, restricting the baryon species to nucleons only, we observe no instability; however, at high densities, the pseudoscalar density-density correlations assume a moat regime, i.e., a damped oscillatory patterned spatial correlation, which in momentum space appears as a nonzero global minimum for some finite three-momentum. When hyperons are permitted to appear, this minimum can cross down to negative values, which configures an instability toward an inhomogeneous pion condensate which ultimately will affect the equation of state.

We investigate the radiative decay $\mathrm{\Upsilon }(10753)\to \gamma X_{b0}$ within the framework of nonrelativistic effective field theory (NREFT). The $\mathrm{\Upsilon }(10753)$ is treated as an $S\text{−}D$ mixed state of the $\mathrm{\Upsilon }(4S)$ and ${\mathrm{\Upsilon }}_1(3{{}^{3}D}_1)$, while the $X_{b0}$ is interpreted as a weakly bound $B\overline{B}$ molecule with $J^{PC}=0^{++}$. The decay process was assumed to occur via the intermediate meson loops involving the $S$-wave $B^{(*)}$ and $P$-wave $B_1^{(\prime )}$ mesons. Our calculated results indicate that the decay $\mathrm{\Upsilon }(10753)\to \gamma X_{b0}$ is dominated by the $B_1^{(\prime )}$ meson loops. The partial decay width is predicted to be 0.2–1.5 keV for a binding energy range of ${\epsilon }_X=0–10\mathrm{MeV}$, corresponding to a branching fraction of ${10}^{-6}-{10}^{-5}$. The decay width is found to be insensitive to the full width of the $B_1^{\prime }$ meson. Our study suggests that the radiative decay of the $\mathrm{\Upsilon }(10753)$ is a promising channel to search for the $X_{b0}$ state, which is crucial for testing heavy quark symmetries and understanding the exotic hadron spectrum in the bottom sector.

The study of heavy-flavor hadrons is topical in the era of precision measurements, which is useful to test theories based on pQCD. The heavy-flavor hadrons are produced initially during heavy-ion or hadronic collisions and are one of the best probes to understand the initial stages of the collisions as well as the system evolution. In experiments, the heavy-flavor sectors are studied directly via their decay to different hadrons or di-leptons or via their semileptonic decay, which is accompanied by additional neutrinos. However, their measurement in experiments is resource intensive and requires input from different Monte Carlo event generators. In this study, we provide an independent method based on machine learning algorithms to separate such leptons coming from heavy-flavor semileptonic decays. We use pythia8 to generate events for this study, which gives a good qualitative and quantitative description of heavy-flavor production in $pp$ collisions. We use the xgboost model for this study, which is trained with $pp$ collisions at $\sqrt{s}=13.6\mathrm{TeV}$. We use ${\mathrm{DCA}}_{\mathrm{xy}}$, ${\mathrm{DCA}}_{\mathrm{Z}}$, and pseudorapidity as the input features to the machine. The ML model provides an accuracy of 98% for heavy-flavor decay electrons and almost 100% for heavy-flavor decay muons.

We present a systematic QCD sum-rule analysis of the in-medium properties of the charged kaon doublet $K^{\pm }$ over the full $(T,\rho )$ plane relevant to current and forthcoming heavy-ion experiments. Working within the QCD sum-rule framework and incorporating temperature- and density-dependent quark, gluon, and mixed condensates, we derive Borel-transformed sum rules for the effective masses $m_{K^{\pm }}$, the pseudoscalar decay constants $f_{K^{\pm }}$, and the vector self-energy ${\mathrm{\Sigma }}_v$ of both charged states simultaneously. Our vacuum results, $m_{K^{-}}={494.6}_{-6.9}^{+4.9}\mathrm{MeV}$ and $f_{K^{-}}={157.3}_{-2.9}^{+4.1}\mathrm{MeV}$ (with near-degenerate $K^{+}$ values), are in excellent agreement with Particle Data Group values at the subpercent level. In the medium, $m_{K^{\pm }}$ decreases monotonically with increasing baryon density and temperature, signaling progressive partial restoration of chiral symmetry. A pronounced mass splitting $\mathrm{\Delta }m=m_{K^{-}}-m_{K^{+}}$ develops in baryonic matter, driven by the opposite sign of the Weinberg–Tomozawa vector interaction for the two charge states; it reaches $|\mathrm{\Delta }m|\sim 0.35\mathrm{GeV}$ near $\rho \simeq 3.2{\rho }_{\mathrm{sat}}$ at $T=0$ and is partially quenched by thermal fluctuations. A central outcome of this study is the extraction of the critical onset density ${\rho }_c$, defined as the threshold beyond which the in-medium modifications of $K^{-}$ properties signal the onset of the transition toward the chirally restored phase. We stress that ${\rho }_c(T)$ should not be interpreted as a precise determination of the QCD critical point—a task beyond the reach of any current effective framework—but rather as an indicator of the density regime where hadronic descriptions begin to break down and quark degrees of freedom become increasingly relevant. With this interpretation, our results reveal a pronounced temperature dependence: ${\rho }_c\simeq (1.2–1.4){\rho }_{\mathrm{sat}}$ for $T\lesssim 100\mathrm{MeV}$, reflecting the robustness of the hadronic phase under cold compression, and a sharp reduction to ${\rho }_c\simeq 0.45{\rho }_{\mathrm{sat}}$ near the pseudocritical temperature $T_c\simeq 155\mathrm{MeV}$. This dramatic downward shift reflects the synergistic destabilization of the chiral condensate by combined thermal and density fluctuations, and establishes temperature as a more efficient driver of chiral restoration than baryon density alone in the regime accessible to current experiments. Our findings provide quantitative, QCD-based theoretical input for interpreting kaon observables at HADES/GSI, CBM/FAIR, STAR/RHIC, and NA61/SHINE/CERN-SPS, and carry direct implications for kaon condensation in neutron star matter and the hadronic equation of state at supranuclear densities.

We formulate the q uantum version of nonprojectable Hořava gravity as a Lagrangian theory with a path integral in the configuration space with an ultralocal in time, but nonlocal in space, field-dependent measure. Using auxiliary fields, we cast the measure into a local form satisfying several bosonic and fermionic symmetries. We perform an explicit one-loop computation in the theory in ($2+1$) dimensions, using for the case study the divergent part of the action on a background with nontrivial shift vector; the background spatial metric is taken to be flat and the background lapse function is set to 1. No truncations are assumed at the level of perturbations, for which we develop a diagrammatic technique and a version of the heat-kernel method. We isolate dangerous linear-in-frequency divergences in the two-point function of the shift, which can lead to spatial nonlocalities, and explicitly verify their cancellation. This leaves a fully local expression for the divergent part of the quadratic effective action, from which we extract the beta functions for the Newton constant and the essential coupling $\lambda$ in the kinetic term of the metric. We formulate the questions that need to be addressed to prove perturbative renormalizability of the nonprojectable Hořava gravity.

We present an operator-algebraic definition for timelike entanglement entropy in quantum field theory under a few mild postulates. This rigorously defined timelike entanglement entropy is real-valued due to the timelike tube theorem. We further demonstrate why the timelike entanglement entropy should be real-valued from both path integral argument and holography perspective.

Observations of neutron stars and the precise measurement of their macroscopic properties have provided valuable insights into fundamental physics, both by constraining the behavior of nuclear matter under extreme conditions and by enabling tests of general relativity in the strong-field regime. In this context, equation-of-state-insensitive or “quasiuniversal” relations between key observables, such as the compactness, dimensionless static tidal deformability, and moment of inertia, play a crucial role in connecting different measurable observables while minimizing uncertainties due to the yet unknown equation of state. In this work, we identify new quasiuniversal relations between the static, dimensionless tidal deformability (${\mathrm{\Lambda }}^{(0)}$) and its leading-order dynamical correction (${\mathrm{\Lambda }}^{(2)}$), as well as between ${\mathrm{\Lambda }}^{(0)}$ and a combination of these parameters ($\sqrt{{\mathrm{\Lambda }}^{(0)}/{\mathrm{\Lambda }}^{(2)}}\equiv M{\omega }_{*}$), obtained from the small-frequency expansion of the relativistic tidal response. We test these relations across a representative set of 59 equations of state, finding that the equation-of-state dependence does not exceed $\sim 5\%$ for the ${\mathrm{\Lambda }}^{(0)}–{\mathrm{\Lambda }}^{(2)}$ relation and $\sim 2.8\%$ for the ${\mathrm{\Lambda }}^{(0)}–M{\omega }_{*}$ relation. This indicates a high degree of universality and offers a simplified framework for incorporating dynamical tidal effects into gravitational-wave modeling. Furthermore, we compare the dynamical tidal response against different recent strategies (a Taylor expansion and a one-mode approximation) to model the dynamical tide. We find that both models are capable of capturing the frequency-dependent behavior of the dynamical tidal deformability, with the one-mode approximation agreeing better with the dynamical response than the Taylor expansion in most of the parameter space.

This work investigates the impact of streams of transient, non-Gaussian noise artifacts or “glitches” on the parameter estimation of extreme mass ratio inspirals (EMRI) in the Laser Interferometer Space Antenna (LISA). Glitches cause biased and less precise inference for short-duration signals such as massive black hole binaries, but their effect on long-lived sources such as EMRIs has not been quantified. Using simulated LISA observations containing injected EMRIs and streams of shapelet-based glitches drawn from the LISA Pathfinder catalog, we estimate the glitch-induced parameter biases and uncertainties through a Fisher-matrix-based analysis whose accuracy we verify with Markov chain Monte Carlo methods. We find that moderately mitigated glitch streams, i.e., ones containing only glitches of up to moderate SNRs ($\rho \lesssim 90$), induce negligible to minor biases $[\sim 0.04\sigma ,\sim 0.6\sigma ]$ in the inferred EMRI parameters. In contrast, weakly mitigated glitch streams containing higher-SNR events ($\rho \lesssim 400$) can produce biases nearing $1\sigma$. These results demonstrate that, when compared to inference of other sources such as massive black hole binaries, EMRI inference is notably more robust to glitches. We stress that at least some amount of glitch modeling and mitigation remains essential for unbiased EMRI analyses in the LISA era.

Astrophysical black holes are usually surrounded by an accretion disk. At least parts of these accretion disks consist of a plasma in which light rays with different energies are dispersed. However, we usually do not know the exact configurations of these plasmas. In this paper we will now use the example of a Schwarzschild black hole embedded in an inhomogeneous pressureless and nonmagnetized plasma to investigate how the structural changes of the photon rings can help us to determine the properties of a plasma surrounding a black hole using multifrequency observations. For this purpose we will use a simple analytic model which describes a plasma whose electron density increases toward the equatorial plane when we approach the event horizon. For the chosen model we will first derive and then analytically solve the equations of motion. Then we will place an observer in the domain of outer communication and introduce an orthonormal tetrad to relate the constants of motion to latitude-longitude coordinates on the observer’s celestial sphere. In the next step we will use the analytic solutions to investigate the geometric structures of the direct image as well as the photon rings of first and second order on the observer’s celestial sphere. We will write down a lens equation and calculate the redshift and the travel time. We will compare the obtained results to results for the direct image and the photon rings in vacuum and in the presence of a homogeneous plasma. Finally, we will discuss which of these quantities can be used to extract information about the properties of the plasma.