Weak gravitational lensing signals of optically identified clusters are impacted by a selection bias—halo triaxiality and large-scale structure along the line of sight simultaneously boost the lensing signal and richness (the inferred number of galaxies associated with a cluster). As a result, a cluster sample selected by richness has a mean lensing signal higher than expected from its mean mass, and the inferred mass will be biased high. This selection bias is currently limiting the accuracy of cosmological parameters derived from optical clusters. In this paper, we quantify the bias in mass calibration due to this selection bias. Using two simulations, MiniUchuu and Cardinal, with different galaxy models and cluster finders, we find that the selection bias leads to an overestimation of lensing mass at the 20–50% level, with a larger bias (20–80%) for large-scale lensing ($>3\mathrm{Mpc}$). Even with a moderate projection model, this selection bias significantly outweighs other currently known cluster lensing systematics. This work confirms the need to account for this bias in future optical cluster cosmology analyses, and we discuss strategies for mitigating this bias.

We present two approaches for “painting” baryonic properties relevant to the Sunyaev-Zel’dovich (SZ) effect—optical depth and Compton-$y$—onto three-dimensional $N$-body simulations, using the MillenniumTNG suite as a benchmark. The goal of these methods is to produce fast and accurate reconstruction methods to aid future analyses of baryonic feedback using the SZ effect. The first approach employs a Gaussian process emulator to model the SZ quantities via a transfer function, while the second utilizes hybrid effective field theory (HEFT) to reproduce these quantities within the simulation. Our analysis involves comparing both methods to the true MillenniumTNG optical depth and Compton-$y$ fields using several metrics, including the cross-correlation coefficient, power spectrum, and power spectrum error. Additionally, we assess how well the reconstructed fields correlate with dark matter haloes across various mass thresholds. The results indicate that the transfer function method yields more accurate reconstructions for fields with initially high correlations ($r\approx 1$), such as between the optical depth and dark matter fields. Conversely, the HEFT-based approach proves more effective in enhancing correlations for fields with weaker initial correlations ($r\sim 0.5$), such as between the Compton-$y$ and dark matter fields. Lastly, we discuss extensions of our methods to improve the reconstruction performance at the field level.

All stars rotate. While magnetic braking slows massive stars, the effect a stellar companion has on stellar rotation is still being explored. To prepare for future observations from rotating core-collapse supernovae (CCSNe), we analyze a set of 30 2D neutrino-radiation hydrodynamic CCSN simulations for a variety of compactness values, rotation rates, and equations of state. We systematically explore how rotation lowers expected neutrino counts and energies for a realistic detector, while accounting for adiabatic Mikheyev-Smirnov-Wolfenstein matter effects. We quantify the effect of viewing angle for neutrino emission for multiple rotation rates. Using “multimessenger synthesis,” we develop a technique that correlates multimessengers to constrain the neutrino mass ordering for a future supernova event. Likewise, we develop a method to constrain the distance to a rotating or nonrotating CCSN, regardless of explosion outcome.

Determining where, when, and how neutrino flavor oscillations must be included in large-scale simulations of hot and dense astrophysical environments is an enduring challenge that must be tackled to obtain accurate predictions. Using an angular moment-based linear stability analysis framework, we examine the different kinds of flavor instabilities that can take place in the context of the postprocessing of a neutron star merger simulation, with a particular focus on the collisional flavor instability and a careful assessment of several commonly used approximations. First, neglecting anisotropies of the neutrino field, we investigate the extent to which commonly used monoenergetic growth rates reproduce the results obtained from a full multienergy treatment. Contrary to the large discrepancies found in core-collapse supernova environments, we propose a simple combination of energy-averaged estimates that reproduces the multienergy growth rates in our representative simulation snapshot. We then quantify the impact of additional physical effects, including nuclear many-body corrections, scattering opacities, and the inclusion of the vacuum term in the neutrino Hamiltonian. Finally, we include the neutrino distribution anisotropies, which allows us to explore, for the first time in a multienergy setting, the interplay between collisional, fast, and slow modes in a moment-based neutron star merger simulation. We find that, despite a dominance of the fast instability in most of the simulation volume, certain regions exhibit only a collisional instability, while others, especially at large distances, exhibit a slow instability that is largely underestimated if anisotropic effects are neglected.

We investigate black hole superradiance evolution of the interacting multiple fields. We consider a model of two scalar fields interacting with a cubic coupling and study the superradiant evolution of the cloud. We demonstrate that superradiance is typically suppressed when the superradiant field couples to another field, even with a very weak coupling strength. This implies that the constraints on dark particles derived from single-field analyses can be revised in the presence of interactions. Moreover, we find that the multifield superradiant evolution and its corresponding observational signatures can be different across parameter spaces, which makes black hole superradiance an even more powerful probe of the dark sector in particle physics.

Pressure isotropy, i.e., equality between radial and tangential pressure, is often assumed when studying neutron stars. However, mechanisms such as pion/kaon condensation, magnetic fields, and dark matter clustering can lead to pressure anisotropy. This work presents a comprehensive measurement of pressure anisotropy in neutron stars. Our analysis incorporates an extensive set of nuclear experimental constraints and multi-messenger astrophysical observations. We find that the Bayes factor for anisotropy against isotropy $\gtrsim 3$:1, when the anisotropy is allowed to vary between individual stars. The posterior indicates a population-wide preference for negative anisotropy, primarily driven by PSR $\mathrm{J}0740+6620$. Due to the lack of radius measurements for $2M_{\odot }$ neutron stars, we cannot rule out density-scale-dependent anisotropy. Therefore, both phase transitions and density-scale-independent mechanisms, such as magnetic fields, dark matter clustering, or deviations from general relativity are viable explanations. While the evidence for anisotropy remains inconclusive, these results demonstrate that pressure anisotropy can be utilized as a tool for identifying missing physics in neutron star modeling or revealing novel physics in the era of multimessenger astronomy.

We perform long-term general relativistic neutrino-radiation hydrodynamic simulations for core-collapse supernovae (CCSNe) which include the cooling effect induced by the coupling between axionlike particles (ALPs) and photons. We take into account the photon coalescence and the Primakoff effect and investigate ALPs with the mass of 10 MeV and the coupling constant $g_{a\gamma }$ of $1.0\times {10}^{-9}–7.0\times {10}^{-9}{\mathrm{Gev}}^{-1}$. Our simulations show that the ALP luminosity exceeds the neutrino luminosity above $g_{a\gamma }=6.0\times {10}^{-9}{\mathrm{Gev}}^{-1}$, which is consistent with the condition used for the ALP search from SN 1987A. We confirm that the effects of the ALP cooling on the neutrino signal emerge in the late phase rather than the accretion phase, as reported in previous studies. We estimate the number of neutrino events and its statistical uncertainty for Super-Kamiokande assuming a 10 kpc CCSN. We find that, when the event number is as low as $\sim 10$, the signature of ALPs can be difficult to find even if the ALP luminosity is as high as the neutrino luminosity, because of the statistical fluctuation.

We present a new, state-of-the-art computation of the diffuse supernova neutrino background (DSNB), where we use neutrino spectra from multidimensional, multisecond core-collapse supernova simulations—including both neutron-star and black-hole forming collapses—and binary evolution effects from modern population synthesis codes. Large sets of numerical results are processed and connected in a consistent manner, using two key quantities, the mass of the star’s carbon-oxygen (CO) core at an advanced precollapse stage—which depends on binary evolution effects—and the compactness parameter, which is the main descriptor of the postcollapse neutrino emission. The method enables us to model the neutrino emission of a very diverse, binary-affected population of stars, which cannot unambiguously be mapped in detail by existing core-collapse simulations. We find that including black hole-forming collapses enhances the DSNB by up to $\sim 50\%$ at $E\gtrsim 30–40\mathrm{MeV}$. Binary evolution effects can change the total rate of collapses, and generate a subpopulation of high core mass stars that are stronger neutrino emitters. However, the net effect on the DSNB is moderate—up to $\sim 15\%$ increase in flux—due to the rarity of these super-massive cores and to the relatively modest dependence of the neutrino emission on the CO core mass. The methodology presented here is suitable for extensions and generalizations, and therefore it lays the foundation for modern treatments of the DSNB.

The model for Oppenheimer-Snyder gravitational collapse in a de Sitter spacetime was investigated by Berens et al. [Phys. Rev. D 105, 064057 (2022).], where theoretical results for the minimal and next-to-minimal models were obtained by imposing initial conditions, and the analysis for the case of nonminimal model remained open. In this work, we revisit the problem of gravitational collapse in massive gravity in a de Sitter spacetime to develop a consistent analysis for generic models. It is found that the location of the apparent horizon where it crosses the surface of the star satisfies a cubic polynomial equation for generic models. We explore rigorously the behavior of all three solution branches, beyond the perturbative approximations, in the generic parameter space and derive explicitly the expressions for the Ricci curvature and density at the star’s boundary. It is found that for the minimal model of massive gravity in a de Sitter spacetime a collapsing solution smoothly recovers the general relativity in the limits of small graviton mass and a flat spacetime, whereas neither the next-to-minimal model nor the nonminimal model recovers the general relativity solution in those limits. We demonstrate that there is a critical mass of a dust ball, above which there exists no Schwarzschild black hole, and only one solution branch that starts from the de Sitter point remains. Remarkably, we find that for the nonminimal model a strong gravitational collapse takes place, where the apparent horizon at the surface crossing vanishes, while both the Ricci curvature and the density blow up.

It was recently discovered that waves scattering off a $Q$ ball can extract energy from it. We present an analytical treatment of this process by adopting a multistep function approximation for the background field, which yields perturbative solutions expressed in terms of Bessel functions. For thin-wall $Q$ balls, the amplification factors reduce to simple sinusoidal functions, which explains the multipeak structure of the spectrum and identifies the physical quantities that determine it. For instance, at high frequencies, the peak spacing is simply the inverse of the $Q$-ball size. The analytical solution further enables us to delineate the full range of possible amplification factors. For general $Q$ balls, this analytical framework also substantially improves the efficiency of evaluating the amplification factors.

This study investigates the excesses observed around 95 GeV in diphoton and $b\overline{b}$ experiments within the framework of the left-right supersymmetric model (LRSSM). Considering the one- and two-loop effective potential corrections to the Higgs masses, the model is able to describe the experimentally observed $\mu (h_{95}{)}_{\gamma \gamma }$ and $\mu (h_{95}{)}_{b\overline{b}}$ signal strengths. In addition, we also present the impacts of the LRSSM-specific parameters $\tan {\beta }_R$, $v_R$, and $v_S$ on the theoretical predictions of the signal strengths for the 95 and 125 GeV neutral Higgs bosons.

The recent low-energy electron recoil (ER) results reported by the LUX-ZEPLIN (LZ) experiment have established the most stringent constraints to date on new physics scenarios, specifically for solar axion-like particles with keV-scale masses and mirror dark matter. Motivated by this enhanced sensitivity and the resulting restrictive limits, our present work focuses on probing light mediator models via elastic neutrino-electron scattering induced by solar neutrinos. We specifically consider two broad classes of new physics scenarios; (i) universal light mediator models consistent with Lorentz invariance, including scalar, vector, and tensor interactions, and (ii) anomaly-free leptophilic $U(1{)}^{\prime }$ gauge extensions featuring a new vector mediator associated with the $L_e-L_{\mu }$, $L_e-L_{\tau }$, $L_{\mu }-L_{\tau }$, and $L_e+2L_{\mu }+2L_{\tau }$ symmetries. By incorporating contributions from these interactions into the neutrino-electron scattering cross section and utilizing the most precise solar neutrino flux predictions, we analyze the latest LZ ER datasets. We report novel constraints on the coupling-mass parameter space for these models. Furthermore, we contextualize our findings by comparing them with established bounds from various laboratory, cosmological, and astrophysical sources. Our analysis demonstrates that LZ data provide significantly improved limits in previously unconstrained regions of the parameter space.

We use lattice field theory to study the finite-volume energy spectrum of the $\pi \pi$ system in $SU(2)$ chiral effective field theory (ChEFT) at leading order in the chiral expansion. This finite-volume spectrum can be directly related to the (infinite-volume) $\pi \pi$ scattering phase shifts by Lüscher’s formula. We compare our results to the finite-volume spectrum obtained from lattice QCD by the RBC-UKQCD Collaboration. Our calculation and the lattice QCD calculation are both performed with the physical pion mass and the same lattice volume (as measured in physical units). However, we find significant differences between the two calculations in the isospin $I=0$ channel. In particular, there is a nearly stable $\sigma$ resonance in our lattice ChEFT calculation, which is absent in the lattice QCD calculation. This likely indicates that ChEFT does not converge well with a naive lattice regularization.

In this work, we study the jet quenching parameter $\widehat{q}$ by using a background field effective theory. Particular attention is paid to its behavior near the critical temperature where nonperturbative effects induced by the deconfining phase transition are taken into account through a self-consistently introduced background field $\mathcal{Q}$. We adopt a theoretical approach in which the interaction rate between the energetic jet and medium partons is computed diagrammatically and the hard-thermal-loop resummed propagator is used to regulate the infrared divergence. In the presence of a background field, its influence on the jet quenching parameter manifests in two aspects. One is the modification on the screening mass in the resummed propagator, which leads to an enhanced $\widehat{q}$. The other corresponds to the $\mathcal{Q}$-modified parton distribution function which is dominant and leads to a suppression of $\widehat{q}$. Decreasing the temperature $T$, our result shows a nonmonotonic $T$ dependence of the dimensionless $\widehat{q}/T^3$. In the high temperature region, $\widehat{q}/T^3$ shows an increase with decreasing $T$ due to the running coupling effect. Near the critical temperature, the background field plays a significant role and a dramatic suppression of $\widehat{q}/T^3$ is found which qualitatively agrees with the lattice simulation. In addition, the background field modification on the jet quenching parameter which is characterized by the $\widehat{q}$ ratio can be simply parametrized by a polynomial expression depending only on the background field. This expression is expected to be useful for phenomenological applications in jet physics.

We present a theoretical analysis of the process ${\mathrm{\Lambda }}_c^{+}\to p{\overline{K}}^0{\pi }^0$ within the chiral unitary approach, with particular emphasis on the dynamically generated $N(1535)$ resonance. In addition to $N(1535)$, our model incorporates contributions from other intermediate resonances including $N(1650)$, $K^{*}(892)$, $K_0^{*}(1430)$, $N(1440)$, and $\mathrm{\Sigma }(1750)$. The calculated invariant mass distributions and Dalitz plot are in good agreement with the recent Belle measurements. Our analysis highlights the crucial role of $N(1535)$ state in this decay channel and supports its interpretation as a dynamically generated state arising from coupled-channel meson-baryon interactions.

A comprehensive study of the $J/\psi$ energy correlator as a probe of nonperturbative hadronization in color-octet $c\overline{c}$ production is performed. The energy correlator measures the energy flow as a function of the angular distance ($\chi$) from the identified $J/\psi$ meson. Using the pythia8 Monte Carlo event generator, the correlator is computed at both parton and hadron levels. At high-$J/\psi$ transverse momentum ($p_T>7\mathrm{GeV}/c$), the parton-level correlator in the $\cos \chi >0$ region is dominated by soft gluon emission during the hadronization of the color-octet state, a contribution clearly distinguishable from other partonic sources, such as underlying multiparton interactions. The transition to the hadron level, however, introduces substantial modifications, suppressing the correlator in this region by approximately an order of magnitude and underscoring the complexity of the hadronization mapping. Further analysis reveals that the hadron-level observable exhibits notable sensitivity to model parameters: increasing the mass splitting between colored $c\overline{c}$ pre-resonances and the $J/\psi$ meson from 0.2 to $0.8\mathrm{GeV}/c^2$ enhances the correlator by up to 60%, while extending the color reconnection range yields a milder enhancement of about 10%. These findings demonstrate that precise measurements of the hadron-level $J/\psi$ energy correlator, when interpreted within robust event-generator frameworks, can provide novel constraints on hadronization dynamics and help clarify the production mechanisms of the $J/\psi$ state.

The quark anomalous magnetic moments (AMMs) are investigated in a two-flavor low-energy effective theory within the functional renormalization group (FRG) approach under an external magnetic field. The Schwinger formalism is adopted for quark propagators, and Fierz-complete four-quark scatterings are self-consistently included through the renormalization group flows. We find that the quark AMMs are dynamically generated with the chiral symmetry breaking, and the magnitude of the AMM of the down quark is around four times larger than that of the up quark. The transverse AMMs and the longitudinal d-quark AMM monotonically decrease with the magnetic field strength, while the longitudinal u-quark AMM slightly increases with the magnetic field strength. At $B=0$, the magnetic moments of proton and neutron are computed using the constituent quark model, which are close to the experimental values.

We investigate the trade-off between vacuum insensitivity and sensitivity to excitations in finite-size detectors, taking measurement locality as a fundamental constraint. We derive an upper bound on the detectability of vacuum excitation, given a small but nonzero probability of false positives in the vacuum state. The result is independent of the specific details of the measurement or the underlying physical mechanisms of the detector and relies only on the assumption of locality. Experimental confirmation or violation of the inequality would provide a test of the axioms of algebraic quantum field theory, offer new insights into the measurement problem in relativistic quantum physics, and establish a fundamental technological limit in local particle detection.

We present an analysis of the processes $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }(1S)$, $\eta \mathrm{\Upsilon }(2S)$, and $\gamma X_b$ with $X_b\to {\pi }^{+}{\pi }^{-}{\chi }_{bJ},{\chi }_{bJ}\to \gamma \mathrm{\Upsilon }(1S)$ ($J=1$, 2) reconstructed from $\gamma \gamma {\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$ $(\ell =e,\mu )$ final states in $19.6{\mathrm{fb}}^{-1}$ of Belle II data collected at four energy points near the peak of the $\mathrm{\Upsilon }(10753)$ resonance. Here, $X_b$ is a hypothetical bottomonium-sector partner of the $X(3872)$. In the process $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }(2S)$, we observe a signal with a significance that exceeds $6.0\sigma$ when all energy points are combined. A signal with a significance of $4.2\sigma$ is observed at a center-of-mass energy of 10.653 GeV, close to the $B^{*}{\overline{B}}^{*}$ threshold. At this energy, we measure $\sigma (\eta \mathrm{\Upsilon }(2S))/\sigma ({\pi }^{+}{\pi }^{-}\mathrm{\Upsilon }(2S))>23$ at the 90% confidence level, indicating a strong violation of heavy-quark spin symmetry. No significant signal is observed for $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }(1S)$ or $\gamma X_b$. Upper limits on the Born cross sections for the processes $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }(1S)$ and $e^{+}{e}^{-}\to \gamma X_b$ with $X_b\to {\pi }^{+}{\pi }^{-}{\chi }_{bJ}$ are determined.