We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we propose calculating a Euclidean version of the degree of polarization for a fast-moving hadron on the lattice, which is ultraviolet finite, and no soft function subtraction is needed. It indicates a practical way to explore the distribution of the linearly polarized gluons in a proton and the linearly polarized gluon effects in hadron collisions on the lattice.

Inspired from perturbative calculations, this work introduces imaginary (${\mathrm{\Omega }}_{\mathrm{I}}$) and real ($\mathrm{\Omega }$) rotation effects to the pure $SU(3)$ gauge potentials simply through variable transformations: the empirical Polyakov loop (PL) potentials can be rewritten as functions of the imaginary chemical potentials of gluons and ghosts $(q_{\mathrm{ij}})$, and the transformations are taken as $q_{\mathrm{ij}}\to q_{\mathrm{ij}}\pm {\mathrm{\Omega }}_{\mathrm{I}}/T$ and $q_{\mathrm{ij}}\to q_{\mathrm{ij}}\pm i\mathrm{\Omega }/T$, respectively. For the PL potential of Fukushima ($V_1$), a smaller imaginary rotation ${\mathrm{\Omega }}_{\mathrm{I}}$ tends to suppress PL at all temperatures, and the deconfinement transition keeps of the first order. However, for the PL potential of the Munich group ($V_2$), ${\mathrm{\Omega }}_{\mathrm{I}}$ tends to enhance PL at low temperature $T$, consistent with lattice simulations, but suppresses PL at high $T$, consistent with perturbative calculations. Moreover, the deconfinement alters from first order to crossover with increasing ${\mathrm{\Omega }}_{\mathrm{I}}$ as is expected from lattice simulations. On the other hand, the real rotation $\mathrm{\Omega }$ tends to enhance PL at relatively low $T$ for both potentials, and the (pseudo)critical temperature decreases with $\mathrm{\Omega }$ as expected. Therefore, we find that analytic continuation of the phase diagram from imaginary to real rotation is not necessarily valid in the nonperturbative region. Finally, we apply the more successful PL potential $V_2$ to the Polyakov–Nambu–Jona-Lasinio model and discover that ${\mathrm{\Omega }}_{\mathrm{I}}$ tends to break chiral symmetry while $\mathrm{\Omega }$ tends to restore it. Especially, the modified model is even able to qualitatively explain the lattice result that a larger $T$ would catalyze chiral symmetry breaking for a large ${\mathrm{\Omega }}_{\mathrm{I}}$.

In general relativity, the use of conformal transformation is ubiquitous and leads to two different frames of reference, known as the Jordan and the Einstein frames. Typically, the transformation from the Jordan frame to the Einstein frame involves introducing an additional scalar degree of freedom, often already present in the theory. We will show that at the quantum level, owing to this extra scalar degree of freedom these two frames exhibit subtle differences that the entanglement between two massive objects can probe.

We investigate the dissipation rate of a scalar field in the vicinity of the phase transition and the ordered phase, specifically within the universality class of model A. This dissipation rate holds significant physical relevance, particularly in the context of interpreting effective potentials as inputs for dynamical transport simulations, such as hydrodynamics. To comprehensively understand the use of effective potentials and other calculation inputs, such as the functional renormalization group, we conduct a detailed analysis of field dependencies. We solve the functional renormalization group equations on the Schwinger-Keldysh contour to determine the effective potential and dissipation rate for both finite and infinite volumes. Furthermore, we conduct a finite-size scaling analysis to calculate the dynamic critical exponent $z$. Our extracted value closely matches existing values from the literature.

In this article, we write down the Berends-Giele (BG) currents for extended gravity explicitly and discuss the unifying relations of these BG currents. This new tool, formally different from the double field theory current, may deepen our understanding of the current Kawai-Lewellen-Tye relation.

Pulsar timing arrays are sensitive to low-frequency gravitational waves (GWs), including the low-frequency stochastic gravitational wave background (GWB), which induces correlated changes in millisecond pulsars’ timing residuals described by the Hellings-Downs curve. Some sources of noise can also induce correlated changes in pulsar timing residuals, albeit with different correlation signatures. A spatial correlation that differs from Hellings-Downs could also be indicative of non-Einsteinian GW polarizations. It is therefore crucial that we be able to characterize the spatial correlation in order to distinguish between the GWB and sources of noise. The optimal statistic (OS) is a frequentist estimator for the amplitude and significance of a spatially correlated signal in PTA data, and it is widely used to search for the GWB. However, the OS cannot perfectly distinguish between different spatial correlations. In this paper, we introduce the multiple component optimal statistic (MCOS): a generalization of the OS that allows for multiple correlations to be simultaneously fit to the data. We use simulated data to show that this method more accurately recovers injected spatially correlated signals, and in particular eliminates the problem of overestimating the amplitude of correlations that are not present in the data. We also demonstrate that this method can be used to recover multiple correlated signals.

Using an adapted version of the sgrid code, we construct for the first time consistent quasiequilibrium configurations for a binary system consisting of two neutron stars in which each is admixed with dark matter. The stars are modeled as a system of two noninteracting fluids minimally coupled to gravity. For the fluid representing baryonic matter the SLy equation of state is used, whereas the second fluid, which corresponds to dark matter, is described using the equation of state of a degenerate Fermi gas. We consider two different scenarios for the distribution of the dark matter. In the first scenario the dark matter is confined to the core of the star, whereas in the second scenario the dark matter extends beyond the surface of the baryonic matter, forming a halo around the baryonic star. The presence of dark matter alters the star’s reaction to the companion’s tidal forces, which we investigate in terms of the coordinate deformation and mass shedding parameters. The constructed quasiequilibrium configurations mark the first step toward consistent numerical-relativity simulations of dark matter admixed neutron star binaries.

Dense environments hosting compact binary mergers can leave an imprint on the gravitational-wave emission which, in turn, can be used to identify the characteristics of the environment. To demonstrate such a scenario, we consider a simple setup of binary black holes with an environment consisting of a scalar-field bubble. We use this as a proxy for more realistic environments and as an example of the simplest physics beyond the standard model. We perform Bayesian inference on the numerical relativity waveforms using state-of-the-art waveform templates for black-hole mergers. In particular, we perform parameter estimation and model selection on signals from black-hole mergers with different mass ratio, total mass, and loudness, hosted by scalar-field bubbles of varying field amplitude. We find that subdominant gravitational-wave modes emitted during the coalescence and ringdown are key to identifying environmental effects. In particular, we find that for face-on signals dominated by the quadrupole mode, the environment is only detectable if both the ringdown and the late inspiral/early merger fall in the detector band; thus, inconsistencies can be found between the inferred binary parameters and those of the final black hole. For edge-on mergers we find that the environment can be detected even if only the ringdown is in band, thanks to the information encoded in the quasinormal mode structure of the final black hole.

We study the scalar probe in the near-horizon region of near-extremal five-dimensional black holes and the problem of reattaching the asymptotic region. We consider the example of a Myers-Perry black hole with two independent angular momenta, for which the problem can be solved analytically in terms of the Riemann $P$-symbols and the confluent Heun special function. By prescribing leaking boundary conditions similar to those considered in the context of Kerr/conformal field theory correspondence, we implement the attachment of the asymptotically flat region, matching the solutions in the near-horizon Myers-Perry geometry with those in the far region. This provides us with a set of explicit expressions for the field response in the background of five-dimensional stationary black holes near extremality, which enables us to highlight qualitative differences with the analogous problem in four dimensions.

Mitigation of the impact of foreground contributions to measurements of cosmic microwave background (CMB) polarization is a crucial step in modern CMB data analysis and is of particular importance for a detection of large-scale CMB $B$ modes. A large variety of techniques, based on different assumptions and aiming at either a full component separation or merely cleaning the foreground signals from the CMB maps, have been described in the literature. In this work, we consider this problem within a unified framework based on the maximum likelihood principle, under the assumption that the signal at each frequency can be represented as a linear mixture of sky templates. We discuss the impact of various additional assumptions on the final outcome of the procedure. We find that the component separation problem can be fully solved in two specific situations: when we either know the frequency scaling of all the components or can correctly model them with a limited number of unknown parameters, as is the case in the parametric component separation techniques; or when we either know the statistical properties of all the components, the foregrounds and CMB, or can correctly model them with a limited number of parameters, as for instance in the spectral matching independent component analysis (SMICA) approach. However, we also show that much less stringent assumptions are sufficient if we only aim at recovering the cleaned CMB signal. In particular, we discuss a “minimally informed” nonparametric method based on maximum likelihood. The method only assumes that the component properties are independent on the sky direction in some, possibly limited, region of the sky and that the CMB covariance is known up to some limited number of parameters. We apply this method to recover the CMB $B$ modes polarization signal in the context of forthcoming CMB experiments and compare its performance with that of the standard parametric maximum likelihood approach. We show that the minimally informed method performs as well as the parametric one when the parametric model is correct, and supersedes it when the it is incorrect.

In this paper, we investigate the process in which axion dark matter undergoes thermal friction, resulting in energy injection into dark radiation, with the aim of mitigating the Hubble tension and large-scale structure tension. In the early Universe, this scenario led to a rapid increase in the energy density of dark radiation; in the late Universe, the evolution of axion dark matter is similar to that of cold dark matter, with this scenario resembling decaying dark matter and serving to ease the large-scale structure tension. We employ cosmological observational data, including cosmic microwave background, baryon acoustic oscillation, supernova data, $H_0$ measurement from SH0ES, and $S_8$ from the Dark Energy Survey Year-3, to study and analyze this model. Our results indicate that the thermal friction model offers partial alleviation of the large-scale structure tension, while its contribution on alleviating Hubble tension can be ignored. The new model yields the value of $S_8$ is $0.795\pm 0.011$ at a 68% confidence level, while the $\mathrm{\Lambda }\mathrm{CDM}$ model yields a result of $0.8023\pm 0.0085$. In addition, the new model exhibits a lower ${\chi }_{\mathrm{tot}}^2$ value, with a difference of −2.60 compared to the $\mathrm{\Lambda }\mathrm{CDM}$ model. Additionally, we incorporate Lyman-$\alpha$ data to reconstrain the new model and find a slight improvement in the results, with the values of $H_0$ and $S_8$ being ${68.76}_{-0.35}^{+0.39}\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ and $0.791\pm 0.011$ at a 68% confidence level, respectively.

We introduce a class of new inflation models within the waterfall region of a generalized hybrid inflation framework. The initial conditions are generated in the valley of hybrid preinflation. Both single-field and multifield inflationary scenarios have been identified within this context. A supersymmetric realization of this scenario can successfully be achieved within the tribrid inflation framework. To assess the model’s viability, we calculate the predictions of inflationary observables using the $\delta N$ formalism, demonstrating excellent agreement with the most recent Planck data. Furthermore, this model facilitates successful reheating and nonthermal leptogenesis, with the matter-field component of the inflaton identified as a sneutrino.

In this work we characterize the performance of a new search technique designed to be sensitive to the remnants of binary neutron star systems. Sensitivity estimates of the new method on simulated data are competitive against those of other works. Previous searches for a gravitational-wave signal from a possible neutron star remnant of the binary neutron star merger event GW170817 have focused on short ($<500\mathrm{s}$) and long duration (2.5 h–8 day) signals. To date, no such post-merger signal has been detected. We introduce a new piecewise model that has the flexibility to accurately follow gravitational-wave signals that are rapidly evolving in frequency, such as those that may be emitted from young neutron stars born from binary neutron star mergers or supernovae. We investigate the sensitivity and computational cost of this piecewise model when used in a fully coherent 1800-second $\mathcal{F}$-statistic search on simulated data containing possible signals from the GW170817 remnant. The sensitivity of the search using the piecewise model is determined using simulated data, with noise consistent with the LIGO second observing run. Across a 100–2000 Hz frequency band, the model achieves a peak sensitivity of $h_{\mathrm{rss}}^{50\%}=4.4\times {10}^{-23}{\mathrm{Hz}}^{-1/2}$ at 200 Hz, competitive with other methods. The computational cost of conducting the search, over a bank of $1.1\times {10}^{12}$ templates, is estimated at 10 days running on 100 CPUs.

Axions, and axionlike particles, have come back into fashion in the last decades as a possible solution to the galactic-scale crisis suffered by the cold dark matter model. In the framework of the wave dark matter model, we have carried out a Jeans analysis on eight dwarf spheroidal galaxies that are orbiting around the Milky Way, and we have constrained the boson mass. Differently to a previous analysis, we adopted an anisotropy parameter that varies with the distance from the center of the galaxy to assess whether this assumption would help to resolve, or at least alleviate, the well-known tension with the value of the boson mass favored by the cosmological analysis. Our results indicate that, differently to what happens in ultrafaint dwarf galaxies, such a tension cannot be lifted introducing a variable anisotropy parameter, leaving as a possible solution the existence of additional axion or axionlike particles with higher masses as naturally predicted in the axiverse.

In this study, we employ the homogeneous balance method to obtain an analytical solution to the Balitsky-Kovchegov equation with running coupling constant. We utilize two distinct prescriptions of the running coupling scale, namely the saturation scale dependent running coupling and the dipole momentum dependent running coupling. By fitting the proton structure function experimental data, we determine the free parameters in the analytical solution. The resulting ${\chi }^2/\mathrm{d}.\mathrm{o}.\mathrm{f}.$ values are determined to be 1.07 and 1.43, respectively. With these definitive solutions, we are able to predict exclusive $J/\psi$ production and demonstrate that analytical solutions with running coupling are in excellent agreement with $J/\psi$ differential and total cross section. Furthermore, our numerical results indicate that the analytical solution of the BK equation with running coupling constant can provide a reliable description for both the proton structure function and exclusive vector meson production.

We study the radiative corrections to the stabilization of the complex structure modulus $\tau$ in modular flavor symmetric models. We discuss the possibility of obtaining the vacuum expectation value of $\tau$ in the vicinity of the fixed point where residual symmetries remain unbroken. As concrete examples, we analyze the one-loop Coleman-Weinberg potential in the $A_4$ modular flavor models. We show that the one-loop correction may lead to the slight deviation from the tree-level result, which may realize a phenomenologically preferred value of the complex structure modulus $\tau$, particularly when the number of species contributing to the one-loop correction is large enough.

We study the hadronic and radiative couplings of the $f_2(1270)$ meson within the hard- and soft-wall models of AdS/QCD. The results for the tensor meson-nucleon-nucleon coupling ($g_{f_{2}NN}$) and tensor meson-photon-vector meson coupling ($g_{f_2\gamma \rho }$) are compared to the ones obtained by using the dispersion relations and amplitude methods, respectively. Qualitative agreement with different analyses implies the reliability of the holographic description of the spin-2 meson.

The difference between fixed-order (FO) and contour-improved (CI) formulations of QCD perturbation theory limits the precision of the strong coupling determined from the hadronic decay of the $\tau$ lepton. Recently, several attempts to understand the mathematical origin of the difference and to solve it by subtracting the dominant infrared renormalon divergence have been made. Motivated by these studies, we review in this paper an improved perturbative QCD expansion, defined some time ago, which also exploits the renormalons by means of a suitable conformal mapping of the Borel plane. In particular, we revisit the convergence of the new expansion by completing the proof presented in a previous paper and showing that the domain of convergence is larger than stated before. We also check the validity of the convergence conditions for the Adler function and the CI and FO expansions of the $\tau$ hadronic spectral function moments, and compare the approach based on conformal mapping with recent solutions to the FO and CI QCD perturbation theory discrepancy proposed in the literature.

With four different type of neutrino-induced interactions, we investigate and reanalyze the Koba-Nielsen-Olesen scaling in modified multiplicity distributions from a different perspective. In a first of its kind attempt, we propose alternate fitting function to parametrize the distribution than the most widely adopted Slattery’s function and compare it with yet another form. We propose the shifted Gompertz and Weibull functions as the fitting functions and compare their potency for the most conventional form of Slattery’s function. In addition, the analysis of the data by evaluating the central moments and factorial moments, we show the dependence of moments on the target size.

We study probes of neutral triple gauge couplings (nTGCs) via $Z^{*}\gamma$ production with off-shell decays $Z^{*}\to \nu \overline{\nu }$ at the LHC and the projected $pp$ (100 TeV) colliders, including both $CP$-conserving (CPC) and $CP$-violating (CPV) couplings. We present the dimension-8 Standard Model effective field theory (SMEFT) operators contributing to nTGCs and derive the correct form factor formulation for the doubly off-shell vertices $Z^{*}\gamma V^{*}$ ($V=Z$, $\gamma$) by matching them with the dimension-8 SMEFT operators. We include new contributions enhanced by the large off-shell momentum of $Z^{*}$, beyond those of the conventional $Z\gamma V^{*}$ vertices with on-shell $Z\gamma$. We analyze the sensitivity reaches for probing the $\mathrm{CPC}/\mathrm{CPV}$ nTGC form factors and the new physics scales of the dimension-8 nTGC operators at the LHC and future 100 TeV $pp$ colliders. We compare our new predictions with the existing LHC measurements of CPC nTGCs in the $\nu \overline{\nu }\gamma$ channel and demonstrate the importance of our new method.