Due to the complexities of the Laser Interferometer Space Antenna (LISA), data gaps arising from instrumental irregularities and/or scheduled maintenance are unavoidable. Focusing on merger-dominated massive black hole binary signals, we test the appropriateness of the Whittle-likelihood on gapped data in a variety of cases. From first principles, we derive the likelihood valid for gapped data in both the time and frequency domains. Cheap-to-evaluate proxies to p-p plots are derived based on a Fisher-based formalism, and verified through Bayesian techniques. Our tools allow us to predict the altered variance in the parameter estimates that arises from noise mismodeling, as well as the information loss represented by the broadening of the posteriors. The result of noise mismodeling with gaps is sensitive to the characteristics of the noise model, with strong low-frequency (red) noise and strong high-frequency (blue) noise giving statistically significant fluctuations in recovered parameters. We demonstrate that the introduction of a tapering window reduces statistical inconsistency errors, at the cost of less precise parameter estimates. We also show that the assumption of independence between intergap segments appears to be a fair approximation even if the dataset is inherently coherent. However, if one instead assumes fictitious correlations in the data stream, when the data segments are actually independent, then the resultant parameter recoveries could be inconsistent with the true parameters. The theoretical and numerical practices that are presented in this work could readily be incorporated into global-fit pipelines operating on gapped data.

We present the first precise calculations of the gravitational quasinormal-mode (QNM) frequencies for spinning black holes with dimensionless angular momenta $J/M^2≔a\lesssim 0.75$ in dynamical Chern-Simons gravity. Using the metric perturbations with spectral methods (METRICS) framework, we compute the QNM frequencies of both axial and polar metric perturbations, focusing on the $nlm=022$, 033, and 032 modes. The METRICS frequencies for the 022 mode achieve numerical uncertainties $\lesssim {10}^{-4}$ when $0\le a\le 0.5$ and $\lesssim {10}^{-3}$ for $0.5\le a\le 0.75$, without decoupling or simplifying the linearized field equations. We also derive optimal fitting polynomials to enable efficient and accurate evaluations of the leading-order frequency shifts in these modes. The METRICS frequencies and fitting expressions are a robust and indispensable step toward enabling gravitational-wave ringdown tests of dynamical Chern-Simons gravity.

In this work, we investigate the generation of primordial black holes (PBHs) within the framework of single-field inflationary models and their compatibility with the cosmological history of the Universe. Our results suggest that, depending on the masses of the formed PBHs, single-field inflation models require more than fine-tuning a potential to induce ultraslow roll; it necessitates a comprehensive understanding of the postinflationary cosmological evolution. As an explicative example, we introduce a new model, based on a double inflection point and consistent with cosmic microwave background observations, capable of generating subsolar PBHs, whose merger could be potentially detectable by the LVK experiment.

We forecast neutrino mass constraints using stage 4 cosmic microwave background (CMB S4) and large-scale structure surveys, focusing on kinetic Sunyaev Zel’dovich (kSZ) tomography as an independent probe of the growth of cosmic structure. We take into account several realistic factors, including the kSZ optical depth degeneracy. Our baseline setup consists of CMB S4 temperature and polarization (but not lensing) information, DESI BAO, the LSST galaxy power spectrum, and a Planck like $\tau$ prior, yielding $\sigma (\sum m_{\nu })=32\mathrm{meV}$. Adding kSZ tomography improves this by a few percent, while a kSZ optical depth prior can push this improvement to over 15%, giving $\sigma (\sum m_{\nu })=27\mathrm{meV}$. When CMB lensing is included in the baseline setup, kSZ does not further improve neutrino mass constraints. We find promising prospects for a scenario combining futuristic CMB and galaxy surveys.

We present a simple field-theory model with reduced invariance under diffeomorphisms whose energy-momentum tensor is identical to the sum of pressureless irrotational matter and a cosmological constant. The model action is built from a single scalar field with a canonical kinetic term without any potential or Lagrange multiplier terms. The coupling to gravity is realized through a particular transverse diffeomorphism invariant volume element. The corresponding sound speed is exactly zero in any background geometry, and the model is dynamically identical to $\mathrm{\Lambda }\mathrm{CDM}$. By restoring the full diffeomorphism invariance through the introduction of Stueckelberg-like fields, we obtain an equivalent local scalar-vector theory.

Measurements of cosmic-ray composition based on air-shower measurements rely mostly on the determination of the position of the shower maximum ($X_{\max }$). One efficient technique is to image the development of the air shower using fluorescence telescopes. An alternative technique that has made significant advances in the recent years is to measure the radio emission from air shower. Common methods for $X_{\max }$ determination in the radio detection technique include fitting a two-dimensional radio intensity footprint at the ground with Monte-Carlo simulated showers which is computationally quite expensive, and others that are based on parametrizations obtained from simulations. In this paper, we present a new method which is computationally extremely efficient and has the potential to reconstruct $X_{\max }$ with minimal input from simulations. The method involves geometrical reconstruction of radio emission profile of air showers along the shower axis by backtracking radio signals recorded by an array of antennas at the ground. On implementing the method on simulated cosmic-ray proton and iron showers in the energy range of ${10}^{17}–{10}^{18}\mathrm{eV}$, we find a strong correlation between the radio emission profile obtained with the method in the 20–80 MHz frequency range and the shower longitudinal profile, implying a new potential way of measuring $X_{\max }$ using radio signals.

Cosmic-ray (CR) streaming instability (CRSI) is believed to play an important role in CR transport and CR feedback to galaxies. It drives the growth of magnetohydrodynamic (MHD) waves that scatter CRs, and leads to energy/momentum exchange between CRs and interstellar medium. Despite extensive research on CRSI, its dependence on the thermodynamic state of the gas and its multidimensional effects have not been systematically studied. In this study, we derive the dispersion relation of the CRSI for three types of MHD waves including their dependence on propagation direction and plasma $\beta$ (the ratio of thermal pressure to magnetic pressure). We verify the analytical dispersion relation with one-dimensional and two-dimensional magnetohydrodynamic particle-in-cell simulations. Furthermore, we use 2D simulations to investigate the role of oblique MHD waves in scattering CRs, and find that these waves are important in helping low-energy particles overcome the 90-degree pitch angle barrier. While magnetosonic waves tend to be damped by transit time damping under typical conditions, oblique Alfvén waves likely play an important role in low-$\beta$ plasmas.

The LIGO-Virgo-KAGRA catalog has been analyzed with an abundance of different population models due to theoretical uncertainty in the formation of gravitational-wave sources. To expedite model exploration, we introduce an efficient and accurate variational Bayesian approach that learns the population posterior with a normalizing flow and serves as a drop-in replacement for existing samplers. With hardware acceleration, inference takes just seconds for the current set of black-hole mergers and readily scales to larger catalogs. The trained posteriors provide an arbitrary number of independent samples with exact probability densities, unlike established stochastic sampling algorithms, while requiring up to three orders of magnitude fewer likelihood evaluations and as few as $\mathcal{O}({10}^3)$. Provided the posterior support is covered, discrepancies can be addressed with smoothed importance sampling, which quantifies a goodness-of-fit metric for the variational approximation while also estimating the evidence for Bayesian model selection. Neural variational inference thus enables interactive development, analysis, and comparison of population models, making it a useful tool for astrophysical interpretation of current and future gravitational-wave observations.

Gravitational wave timbre, the relative amplitude and phase of the different frequency harmonics, can change due to interactions with low-mass halos. We focus on binaries in the LISA range and find that the integrated lens effect of cold dark matter structures can be used to probe the existence of $M_{\mathrm{v}}\lesssim 10M_{\odot }$ halos if a single binary with eccentricity $e=0.3–0.6$ is detected with a signal-to-noise ratio $100-{10}^3$ and it is at $z_s=0.5$.

We explore two longitudinal single-spin asymmetries induced from parity violation in neutral-current deep inelastic scattering at the proposed electron-ion collider in China (EicC): $A_{\mathrm{PV}}^{e(p)}$ from longitudinally polarized (unpolarized) electrons scattering off unpolarized (longitudinally polarized) protons. We find $A_{\mathrm{PV}}^e$, of $\mathcal{O}({10}^{-4})$, is generically 1 to 3 orders of magnitude larger than $A_{\mathrm{PV}}^p$. We further estimate different uncertainty sources including statistics, parton distribution functions, and beam polarization, for both asymmetries, and then identify individually their dominance in different regimes of the Bjorken-$x$. Based on these results, we then advocate utilizing $A_{\mathrm{PV}}^p$ for the extraction of the weak mixing angle at two representative momentum transfer scales unexplored before, and we find a relative precision below 10% can be achieved at the EicC with an effective one-year operation time.

We discuss the hard dense loop perturbation theory approach for studying the thermodynamics of strongly magnetized dense quark matter. The free energy of quarks and gluons have been calculated for one-loop quark and gluon self-energies, respectively. The longitudinal and transverse components of pressure, magnetization, second-order quark number susceptibility, and speed of sound have been computed, and their behavior with chemical potential and magnetic field has been analyzed. Our numerical results show that the longitudinal pressure increases with chemical potential and magnetic field, while for the transverse component, it is diminished. We also analyze the longitudinal component of the speed of sound at high chemical potentials, which approaches the speed of light in the asymptotic limit. The obtained results may be helpful in studying magnetized quark matter in the core of neutron stars and magnetars.

In this work, we investigate in a quantitative way how much radiative corrections to the matter potential for neutrino oscillations can impact the sensitivity to neutrino mass ordering in long-baseline accelerator experiments. Using numerical simulations for the future experiment DUNE, we find that the statistical significance for excluding the incorrect mass ordering can be enhanced by about $0.4\sigma$ if a one-loop correction of 2.0%—based on the Fermi coupling constant $G_{\mu }$ derived from measurements of muon lifetime—is included. The radiative corrections at one-loop level lead to resolving the neutrino mass ordering at $5\sigma$ confidence level 4–9 days earlier than at tree level. In contrast, the sensitivity to leptonic $CP$ violation in DUNE is essentially unchanged. Finally, we emphasize that one-loop corrections should be incorporated into analyses of future neutrino oscillation data in a consistent and systematic manner.

We investigate the LHC discovery prospects for a second Higgs doublet through $A\to ZH$ weak decay. The latter is identified as the smoking gun signature of two Higgs doublet models (2HDMs) with first-order electroweak (EW) phase transition, a necessary condition for EW baryogenesis. In the general 2HDM (G2HDM) that has flavor-changing neutral Higgs couplings, $H$ may decay dominantly via $t\overline{c}+\overline{t}c$ final states, giving rise to trilepton signals. By a phenomenological analysis, we show that $A\to ZH$ in ${\ell }^{+}{\ell }^{-}t\overline{c}$ or ${\ell }^{+}{\ell }^{-}\overline{t}c$ final states could be a promising probe of G2HDM at the LHC with flavor violation.

In this work, we revisit the possible new physics solutions by analyzing the observables associated with $B\to D^{(*)}\tau {\overline{\nu }}_{\tau }$ decays. To explore the structure of new physics, the form factors of $B\to D^{(*)}$ decays play a crucial role. In this study, we utilize the form factor results obtained from a simultaneous fit to Belle data and lattice QCD calculations. Using these form factors, we conduct a global fit of the new physics Wilson coefficients, incorporating the most recent experimental data. Additionally, we use the form factors and Wilson coefficients to make predictions for physical observables, including the lepton flavor universality ratio $R_{D^{(*)}}$, polarized observables, and the normalized angular coefficients $⟨I⟩$’s related to the fourfold decays $B\to D^{*}(\to D\pi ,D\gamma )\tau {\overline{\nu }}_{\tau }$. These predictions are calculated in both model independent scenarios and for three different leptoquark models.

We present a lattice quantum chromodynamics (QCD) determination of the vector and axial-vector form factors that describe the charm-baryon semileptonic decays ${\mathrm{\Xi }}_c\to \mathrm{\Xi }{\ell }^{+}{\nu }_{\ell }$. The calculation uses a domain-wall action for the up, down, and strange quarks, and an anisotropic clover action for the charm quark. We use four ensembles of gauge-field configurations generated by the RBC and UKQCD collaborations, with lattice spacings between 0.111 and 0.073 fm and pion masses ranging from 420 to 230 MeV. We present Standard Model predictions for the decay rates and branching fractions of ${\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}_c^{-}{\ell }^{+}{\nu }_{\ell }$ and ${\mathrm{\Xi }}_c^{+}\to {\mathrm{\Xi }}_c^0{\ell }^{+}{\nu }_{\ell }$ for $\ell =e$, $\mu$. In particular, we obtain $\mathrm{\Gamma }({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{e}^{+}{\nu }_e)/|V_{cs}{|}^2=0.2515(73){\mathrm{ps}}^{-1}$ and $\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{e}^{+}{\nu }_e)=3.58(12)\%$. These values are higher than those predicted by a previous lattice calculation and substantially higher than the experimentally measured values, but consistent with expectations from approximate $SU(3)$ flavor symmetry.

We compute the differential cross section for inclusive ${\mathrm{D}}^0$ production in ultraperipheral collisions within the color glass condensate framework. Our predictions are found to be in relatively good agreement with the compact muon solenoid data at small transverse momentum, which is the region of validity of our approach. Furthermore, we quantify saturation effects by a nuclear modification ratio $R_{pA}$ for ${\mathrm{D}}^0$ photoproduction and examine both analytically and numerically the collinear factorization limit of the ${\mathrm{D}}^0$ differential photoproduction cross section.

A series of vector charmonium(like) states, accompanied by a $K$ meson, have been observed in the decays of $B$ meson. These processes are color-suppressed at the quark level, as inferred from topological diagram analysis. In this work, we calculate the branching fractions of the decays $B\to \psi K$, where $\psi$ denotes the charmonium(like) states $\psi (1S)$, $\psi (2S)$, $\psi (4040)$, $\psi (3770)$, and $\psi (4160)$. Our analysis incorporates both short-distance (naive factorization approach) and long-distance (final-state interactions) contributions. Within reasonable parameters, our results align with experimental data except for the $\psi (4160)$, suggesting its possible exotic nature. Furthermore, we find that long-distance contributions dominate these decay processes, highlighting the crucial role of final-state interactions in the productions of charmonium(like) states in $B$ decays.

We present an improved evaluation of the two-photon exchange correction to the unpolarized lepton-proton elastic scattering process at very low-energies relevant to the MUSE experiment, where only the dominant intermediate elastic proton is considered. We employ the framework of heavy baryon chiral perturbation theory and invoke the soft-photon approximation in order to reduce the intricate 4-point loop-integrals into simpler 3-point loop-integrals. In the present work, we adopt a more robust methodology compared to an earlier work along the same lines for analytically evaluating the loop-integrations, and incorporate important corrections at next-to-next-to-leading order. These include the proton’s structure effects which renormalize the proton-photon interaction vertices and the proton’s propagator. Finally, our results allow a model-independent estimation of the charge asymmetry for the scattering of unpolarized massive leptons and antileptons.

It is demonstrated that two-photon exchange (TPE) corrections to the cross-section of unpolarized semi-inclusive deep-inelastic scattering generate azimuthal-dependent terms and the corresponding $⟨\cos (n\varphi )⟩$ moments. A quark-diquark model of a nucleon was used in the calculations along with a soft-photon approximation. The infrared divergences in the intermediate steps of calculation are regularized with the fictitious photon mass that cancels out in the final result when the soft-photon bremsstrahlung process and interference terms are added. The calculations employ the Mathematica looptools package to evaluate the loop integrals. TPE corrections are analyzed in the kinematics of planned experiments at Jefferson Lab.