Ultralight bosonic dark matter (UBDM) can be described by a classical wavelike field oscillating near the Compton frequency of the bosons. If a measurement scheme for the direct detection of UBDM interactions is sensitive to a signature quadratic in the field, then there is a near-zero-frequency (dc) component of the signal. Thus, a detector with a given finite bandwidth can be used to search for bosons with Compton frequencies many orders of magnitude larger than its bandwidth. This opens the possibility of a detection scheme analogous to Hanbury Brown and Twiss intensity interferometry. Assuming that the UBDM is virialized in the Galactic gravitational potential, the random velocities produce slight deviations from the Compton frequency. These result in stochastic fluctuations of the intensity on a timescale determined by the spread in kinetic energies. In order to mitigate ubiquitous local low-frequency noise, a network of sensors can be used to search for the stochastic intensity fluctuations by measuring cross-correlation between the sensors. This method is inherently broadband, since a large range of Compton frequencies will yield near-zero-frequency components within the sensor bandwidth that can be searched for simultaneously. Measurements with existing sensor networks have sufficient sensitivity to search experimentally unexplored parameter space.

We study the possibility of probing the existence of a light, invisible, axionlike particle (ALP) $a$ in leptonic decays of the $Z$ boson at the proposed high-energy $e^{+}{e}^{-}$ colliders, Circular Electron-Positron Collider (CEPC) and Future Circular Collider (FCC-ee). Both projects plan to run at the $Z$ pole, collecting ${10}^{12}–{10}^{13}$ visible $Z$ decays. We show that, searching for the emission of an invisible ALP from leptons in leptonic $Z$ decays, this enormous statistics could allow us to constrain the ALP couplings to leptons at an unprecedented level for laboratory experiments. In particular, within a Monte Carlo simulation framework, we estimate that CEPC/FCC-ee can be sensitive to the coupling of an invisible ALP to muons up to $f_a/C_{\mu \mu }^A\approx 1\mathrm{TeV}$—where $f_a$ is the ALP decay constant—corresponding to $\mathrm{BR}(Z\to {\mu }^{+}{\mu }^{-}a)\approx 3\times {10}^{-11}$.

We investigate the possible sizes of all the $CP$-violating asymmetries offered by the angular distribution of rare decay ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }(\to p{\pi }^{-}){\ell }^{+}{\ell }^{-}$ in the Standard Model and new physics scenarios motivated by the recent $b\to s{\ell }^{+}{\ell }^{-}$ anomalies. We work in a model-independent effective theory framework and discuss the sensitivity of $CP$ asymmetries to new $O_{9,10}$ operators and their chirality flipped counterparts. We find that the size of many of the $CP$ asymmetries can be at the level of a few percent in new physics scenarios consistent with current $b\to s{\ell }^{+}{\ell }^{-}$ data at a level of $1\sigma$. We emphasize that measurements of these $CP$ asymmetries can be used to discriminate different new physics scenarios in $b\to s{\ell }^{+}{\ell }^{-}$.

We study the properties of the lowest multiplet of light-flavor tensor meson resonances, i.e., $f_2(1270)$, $a_2(1320)$, $K_2^{*}(1430)$, and $f_2^{\prime }(1525)$, within the resonance chiral theory approach. The higher-order resonance chiral operators, including the light-quark mass and $1/N_C$ corrections, are simultaneously incorporated in our study. The use of resonance chiral expressions allows us to analyze not only the relevant experimental data but also in the meantime the lattice results at unphysical quark masses, including the masses of the lowest multiplet of tensor resonances and their decay widths into two pseudoscalar mesons. In addition, the radiative decays of the tensor resonances into one photon plus one pseudoscalar meson and two photons are also studied.

In this paper, we compare several event classification architectures defined on the point cloud representation of collider events. These approaches, which are based on the frameworks of Deep Sets and edge convolutions, circumvent many of the difficulties associated with traditional feature engineering. To benchmark our architectures against more traditional event classification strategies, we perform a case study involving Higgs boson decays to tau leptons. We find a 2.5 times increase in performance compared to a baseline ATLAS analysis with engineered features. Our point cloud architectures can be viewed as simplified versions of graph neural networks, where each particle in the event corresponds to a graph node. In our case study, we find the best balance of performance and computational cost for simple Parwise architectures, which are based on learned edge features.

We apply a suitable replica technique to develop a perturbative expression for the entanglement negativity of bipartite mixed states in $\mathrm{T}\overline{\mathrm{T}}$-deformed ${\mathrm{CFT}}_2\mathrm{s}$ up to the first order in the deformation parameter. Utilizing our perturbative construction we compute the entanglement negativity for various bipartite mixed states involving two disjoint intervals, two adjacent intervals, and a single interval in a $\mathrm{T}\overline{\mathrm{T}}$-deformed ${\mathrm{CFT}}_2$ at a finite temperature, in the large central-charge limit. Subsequently, we advance appropriate holographic constructions to compute the entanglement negativity for such bipartite states in $\mathrm{T}\overline{\mathrm{T}}$-deformed thermal ${\mathrm{CFT}}_2\mathrm{s}$ dual to BTZ black holes in a finite cutoff bulk geometry and find agreement with the corresponding field theoretic results in the limit of small deformation parameter.

The conflicts between quantum mechanics and general relativity have inspired people to search for quantum theories of gravity. If gravitons, as predicted by such theories, exist, it is natural to ask the following questions: Can gravitons carry quantized orbital angular momentum (OAM)? Can they be entangled with each other and with other particles in high-dimensional states? Here we answer these questions by studying the phenomenon of twisting and entangling gravitons in high-dimensional OAM states by possible photon-graviton conversion. The quantum aspect of this phenomenon indicates entanglement oscillation between photons, gravitons, and their hybrids and may lead to the potential development of high-dimensional gravitational wave (GW) communications. In addition, we investigate the phenomenon that photons in the early Universe may be imprinted with OAM information from plasma vortices and turned into OAM gravitons by the presence of possible strong magnetic fields. The resultant OAM GW may exist in the current Universe and provide a novel way of studying the plasma vortex structure in the early Universe.

In this work we comment in more detail on what happens to the parametrized framework first presented by Cardoso et al. when there are departures from the Schwarzschild background metric, as well as possible deviations in the “dynamics.” We treat possible deviations in the background metric with additional coefficients with respect to the original works. The advantages of this reformulation are clear when applied to a parameter estimation problem, since the coefficients are always real, and many of them do not depend on the overtone number and angular momentum of the frequency, thus eventually reducing the total amount of parameters to be inferred.

Eccentricity has become an increasingly important parameter in gravitational wave studies as it can clearly reflect the dynamics of compact object mergers. Obtaining an accurate and fast gravitational waveform template is of paramount importance for accurately estimating gravitational wave parameters. This paper aims to conduct an extensive study of the phenomenological fitting model proposed by Setyawati and Ohme [Phys. Rev. D 103, 124011 (2021)] for adding eccentricity into quasicircular orbital waveforms. We expand the scope of this research by studying the waveform for a mass ratio range of [1, 7], an initial eccentricity range of [0, 0.4], and a continuous time period beyond the fixed time period of $[-1500M,-29M]$. We also investigate the model in higher-order harmonic modes, as well as spin-aligned and spin-precessing waveforms. After expanding some fitting parameters, we have discovered that the model can be applied to mass ratios $q\in [1,7]$. Additionally, it can be applied to almost the entire time period of numerical relativity, including up to $12000M$ prior to merger. It can accommodate higher eccentricities up to $e_0=0.4$, but its accuracy decreases with increasing initial eccentricity. For a specific initial eccentricity $e_0$ and time period such as $[-2000M,-300M]$, mismatches obtained are approximately less than ${10}^{-4}$ for $e_0\in [0,0.1]$, less than ${10}^{-3}$ for $e_0\in [0.1,0.2]$, less than ${10}^{-2}$ for $e_0\in [0.2,0.3]$, and less than ${10}^{-1}$ for $e_0\in [0.3,0.4]$ for mass ratio 1-3, and an order of magnitude worse for mass ratio 4-7. The dependence of the mismatch on eccentricity is due to the fact that as the initial eccentricity increases, the eccentricity estimator $e_X$ deviates further from the expected cosine function, leading to a larger deviation in the morphology of the eccentric waveform and a reduced accuracy in the model’s fitting. It can be applied to higher-order modes and yields similar overlap results. Furthermore, by introducing a shift parameter $g$, it can be approximately applied to spin-aligned waveforms. After obtaining spin-precession effects for the special case of strong precession, our model can also be applied to the general spin-precessing case. In summary, this phenomenological model allows for the construction of eccentric gravitational wave templates for nonspinning, spin-aligned or spin-precessing binary systems. It provides an efficient method for generating templates and sheds light on the phenomenological and universal relationship between eccentric and quasicircular waveforms.

We study charged and rotating boson stars in five-dimensional Einstein-Maxwell-Chern-Simons theory assuming the two angular momenta associated with the two orthogonal planes of rotation to be equal. Next to the angular momenta, the boson stars carry an electric charge and a magnetic moment. Interestingly, we find new branches of Einstein-Maxwell-Chern-Simons solutions for which the spatial part of the gauge potential possesses nodes. Consequently, the magnetic moment and the gyromagnetic ratio have opposite signs as compared to the solutions on the main branch. For sufficiently large energy density we find that the solutions possess ergoregions.

We test the generalized scalar tensor theory in static systems, namely galaxy clusters. The degenerate higher-order scalar-tensor (DHOST) theory modifies the Newtonian potential through effective Newtonian constant and ${\mathrm{\Xi }}_1$ parameter in the small scale, which modifies the hydrostatic equilibrium. We utilize the well-compiled X-COP catalog consisting of 12 clusters with intracluster medium (ICM) pressure profile by Sunyaev-Zel’dovich effect data and temperature profile by x-ray data for each cluster. We perform a fully Bayesian analysis modeling Navarro-Frenk-White (NFW) for the mass profile, and the simplified Vikhlinin model for the electron density. Carefully selecting suitable clusters to present our results, we find a mild to moderate, i.e., $\sim 2\sigma$ significance for a deviation from the standard scenario in four of the clusters. However, in terms of Bayesian evidence, we find either equivalent or mild preference for GR. We estimate a joint constraint of ${\mathrm{\Xi }}_1=-0.030\pm 0.043$ using eight clusters, for a modification from a $\mathrm{\Lambda }\mathrm{CDM}$ scenario. This limit is in very good agreement with theoretical ones and an order of magnitude more stringent than the previous constraint obtained using clusters. We also quote a more conservative limit of ${\mathrm{\Xi }}_1=-0.061\pm 0.074$. Finally, we comment on the tentative redshift dependence of the ${\mathrm{\Xi }}_1$ parameter.

We present analytical solutions describing a family of both inwardly and outwardly spiralling orbits in the Kerr spacetime. The solutions are exact and remarkable for their simplicity. These orbits all have the angular momentum and energy of a circular orbit at some radius $r_c$, but are not restricted to remaining on that circular orbit, a property not possible in Newtonian gravity. We demonstrate that there are five distinct orbital solutions which terminate at the black hole singularity, and three solutions which either escape to infinity or remain bound. The different orbital solutions are characterized entirely by the black hole spin $a$ and the location of $r_c$. Photon orbits spiralling into or out of their (unstable) circular orbit radii are also analyzed. These have properties similar to the hyperbolic class of massive particle orbits discussed herein.

CMB lensing maps probe the mass distribution in projection out to high redshifts, but significant sensitivity to low-redshift structure remains. In this paper we discuss a method to remove the low-redshift contributions from CMB lensing mass maps by subtracting suitably scaled galaxy density maps, nulling the low redshift structure with a model-insensitive procedure that is similar to delensing. This results in a high-$z$-only mass map that can provide a probe of structure growth at uniquely high redshifts: if systematics can be controlled, we forecast that CMB-S4 lensing combined with a Rubin-LSST-like galaxy survey can probe the amplitude of structure at redshifts $z>3.75$ ($z>5$) to within 2.3% (3.3%). We then discuss other example applications of such high-$z$ CMB lensing maps. In standard analyses of CMB lensing, assuming the wrong dark energy model (or wrong model parametrization) can lead to biases in neutrino mass constraints. In contrast, we show with forecasts that a high-$z$ mass map constructed from CMB-S4 lensing and LSST galaxies can provide a nearly model-independent neutrino mass constraint, with only negligible sensitivity to the presence of nonstandard dark energy models, irrespective of their parametrization.

We revisit the scenario of primordial black hole (PBH) formation from large curvature perturbations generated during the waterfall phase transition in hybrid inflation models. In a minimal setup considered in the literature, the mass and abundance of PBHs are correlated and astrophysical size PBHs tend to be overproduced. This is because a longer length scale for curvature perturbations (or a larger PBH mass) requires a longer waterfall regime with a flatter potential, which results in overproduction of curvature perturbations. However, in this paper, we discuss that the higher-dimensional terms for the inflaton potential affect the dynamics during the waterfall phase transition and show that astrophysical size PBHs of the order of ${10}^{17-23}\mathrm{g}$ (which can explain the whole dark matter) can form in some parameter space consistently with any existing constraints. The scenario can be tested by observing the induced gravitational waves from scalar perturbations by future gravitational wave experiments, such as LISA.

Measurements of weak gravitational lensing at low redshifts ($z\lesssim 0.5–1$), quantified by the parameter $S_8$, favor weaker matter clustering than that expected from the standard $\mathrm{\Lambda }$ cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) cosmological model with the parameters determined by cosmic microwave background (CMB) measurements. However, the amplitude of matter clustering at higher redshifts, as probed by lensing of the CMB, is consistent with $\mathrm{\Lambda }\mathrm{CDM}$. In the literature, it has been found that the tension can be resolved by introducing a friction between dark matter and dark energy without altering the tightly constrained expansion history. Here, we show that in order to get a low $S_8$ value consistent with the findings of cosmic shear under $\mathrm{\Lambda }\mathrm{CDM}$, cosmological measurements favor (at $\sim 3\sigma$, in this one parameter model) a nonzero drag leading to a suppression of low-redshift power right precisely around the transition from matter to dark-energy domination. Our results hint at a connection between the $S_8$ tension and the long-standing “cosmic coincidence problem.” We suggest ways to further probe the scenario.

In this paper, we present a refined calculation of the atmospheric neutrino flux spanning from GeV to PeV energies. Our method, Daemonflux, utilizes data-driven inputs and incorporates adjustable parameters to take their uncertainties into account. By optimizing these parameters using a combination of muon data and constraints from fixed-target experiments, we achieve uncertainties in the calculated neutrino fluxes of less than 10% up to 1 TeV, with neutrino ratios constrained to below 10%. Our model performs particularly well at energies below 100 GeV, where the smallest errors are obtained. We make our model available as a software package that provides access to predictions of fluxes, ratios, and errors, including the covariance matrix obtained from the fit.

One of the primary targets of third-generation (3G) ground-based gravitational wave (GW) detectors is detecting the stochastic GW background (SGWB) from early Universe processes. The astrophysical foreground from compact binary mergers will be a major contamination to the background, which must be reduced to high precision to enable the detection of the primordial background. In this work, we revisit the limit of foreground reduction computed in previous studies, point out potential problems in previous foreground cleaning methods, and propose a novel cleaning method subtracting the approximate signal strain and removing the average residual power. With this method, the binary black hole foreground is reduced with fractional residual energy density below ${10}^{-4}$ for frequency $f\in (10,{10}^2)\mathrm{Hz}$, below ${10}^{-3}$ for frequency $f\in ({10}^2,{10}^3)\mathrm{Hz}$ and below the detector sensitivity limit for all relevant frequencies in our simulations. Similar precision is achieved to clean the foreground from binary neutron stars (BNSs) that are above the detection threshold, so that the residual foreground is dominated by subthreshold BNSs, which will be the next critical problem to solve for detecting the primordial SGWB in the 3G era.

Standard Model extensions with a strongly coupled dark sector can induce high-multiplicity states of soft quarks. Such final states trigger extremely efficient antinucleus formation. We show that dark matter annihilation or decay into a strongly coupled sector can dramatically enhance the cosmic-ray antinuclei flux—by six orders of magnitude in the case of ${}^4\overline{\mathrm{He}}$. In this work, we argue that the tentative ${}^3\overline{\mathrm{He}}$ and ${}^4\overline{\mathrm{He}}$ events reported by the AMS-02 Collaboration could be the first sign of a strongly coupled dark sector observed in nature.

Neutrinos allow the probing of stellar interiors during core collapse, helping to understand the different stages and processes in the collapse. To date, supernova neutrinos have only been detected from a single event, SN1987A. Most studies from then on have focused on two distance extremes; Galactic/local supernovae and all past cosmic supernovae forming the diffuse supernova neutrino background. We focus on the intermediate distance regime as a target for detecting core-collapse supernova neutrinos at next generation detectors like Hyper-Kamiokande. To quantify the significance of neutrino detections, we draw on expected discoveries by surveys of near galaxies as well as large synoptic surveys to monitor for optical counterparts of core-collapse supernovae. We find that detection prospects require approximately ten years of operation. We discuss how the ability of electromagnetic surveys to pinpoint the time of core collapse to within the timescale of hours is key for confident neutrino detections. Transient surveys like DLT40 which frequently observe nearby galaxies can help with such crucial information.