In this paper, the classical and quantum theory of $\mathcal{N}=1$ supergravity in four spacetime dimensions will be studied in the framework of loop quantum gravity. We discuss the canonical analysis of the supergravity Holst action as first introduced by Tsuda. In this way, we also derive a compact expression of the supersymmetry constraint, which plays a crucial role in canonical supergravity theories, akin to the role of the Hamiltonian constraint in nonsupersymmetric generally covariant theories. The resulting theory is then quantized using loop quantum gravity methods. In particular, we propose and discuss a quantization of the supersymmetry constraint and derive explicit expressions of the action of the resulting operator. This is important as it is the first step on the way to analyzing the Dirac algebra generated by supersymmetry and Hamiltonian constraint in the quantum theory and for finding physical states. We also discuss some qualitative properties of such solutions of the SUSY constraint.

We provide a theoretical model of $F(R)$ gravity in which it is possible to describe in a unified way inflation, an early and a late dark energy era, in the presence of a light axion particle which plays the role of the dark matter component of the Universe. Particularly, the early time phenomenology is dominated by an $R^2$ term, while the presence of the other terms $f(R)$ ensure the occurrence of the early and late-time dark energy eras. The inflationary phenomenology is compatible with the Planck 2018 data for inflation, while the late-time dark energy era is compatible with the Planck 2018 constraints on the cosmological parameters. Also, the model exhibits an early dark energy era, at $z\sim 2.5$ approximately, followed by a deceleration era, which starts at approximately $z\sim 1.5$, which in turn is followed by a late-time dark energy era for redshifts $z\sim 0.5$, which lasts for approximately 5 billion years up to present time. A notable feature of our model is that the dark energy era is free from dark energy oscillations, at least in the redshift interval $z=[0,10]$. In addition, we also discuss several features related to observational data at $z\sim 2.34$, at which redshift intricate observational data exist in the literature. Moreover, the numerical code for the dark energy phenomenology, written in python3, is presented in the end of the article. Finally, the model has another interesting characteristic, a sudden jump of the value of the Hubble rate in the redshift interval $z\sim [2,2.6]$ where its value suddenly increases and then decreases until $z\sim 0$.

A vitally important requirement for detecting gravitational-wave (GW) signals from compact binary coalescences (CBCs) with high significance is the reduction of the false-alarm rate of the matched-filter statistic. The data from GW detectors contain transient noise artifacts, or glitches, which adversely affect the performance of search algorithms, especially for finding short-lived astrophysical signals, by producing false alarms, often with high signal-to-noise ratio (SNR). These noise transients particularly affect the CBC searches, which are typically implemented by cross-correlating detector strain data with theoretically modeled waveform templates, chosen from a template bank that is densely populated to cover the source parameter ranges of interest. Owing to their large amplitudes, many of the glitches can produce detectably large peaks in the SNR time series—termed “triggers”—in spite of their small overlap with the templates. Such glitches contribute to the false alarms. Historically, the traditional ${\chi }^2$ test has proven quite useful in distinguishing triggers arising from CBC signals and those caused by glitches. In a recent paper, a unified origin for a large class of ${\chi }^2$ discriminators was formulated, along with a procedure to construct an optimal ${\chi }^2$ discriminator, especially when the glitches can be modeled. A large variety of glitches that often occur in GW detector data can be modeled as sine-Gaussians, with quality factor and central frequency, ($Q,f_0$), as parameters. An important feature of a sine-Gaussian glitch is that there is a lag between its time of occurrence in the GW data and the time of the trigger it produces in a templated search. Therefore, this time lag is the third parameter used in characterizing the glitch. The total number of sampled points in the glitch parameter space is associated with the degrees of freedom (d.o.f.) of the ${\chi }^2$. We use singular value decomposition to identify the most significant d.o.f., which helps keep the computational cost of our ${\chi }^2$ down. Finally, we utilize the above insights to construct a ${\chi }^2$ statistic that optimally discriminates between sine-Gaussian glitches and CBC signals. We also use receiver-operating characteristics to quantify the improvement in search sensitivity when it employs the optimal ${\chi }^2$ compared to the traditional ${\chi }^2$. The improvement in detection probability is by a few to several percentage points, near a false-alarm probability of a few times ${10}^{-3}$, and holds for binary black holes with component masses from several to a hundred solar masses. Moreover, the glitches that are best discriminated against are those that are like sine-Gaussians with $Q\in [25,50]$ and $f_0\in [40,80]\mathrm{Hz}$.

We test a model associated with the Einstein gravity modified by using the linear Nash perturbations of the background metric. By means of a Markov chain Monte Carlo (MCMC) modeling, we combine the recent Dark Energy Survey (DES Y1) with the baryon acoustic oscillations (BAO) measurements and a larger datasets of “Gold 2018” growth data, the Planck $2018/\mathrm{\Lambda }\mathrm{CDM}$ parameters on the cosmic microwave background (CMB), the Pantheon Supernovae type Ia and the Hubble parameter data with redshift ranging from $0.01<z<2.3$ to derive the related constraints on the model parameters. We use the Jeffreys’ scale to perform the Akaike information criterion (AIC) to ascertain the statistical viability of the model in comparison with the standard $\mathrm{\Lambda }\mathrm{CDM}$ model. We find a mild reduction of the ${\sigma }_8$ discrepancy between the best-fit values of growth-rate amplitude factor and the matter content $({\sigma }_8-{\mathrm{\Omega }}_m)$ of the observations from CMB and large scale structure (LSS) probes. Due to the degeneracy of the model parameters, this situation may be improved. Oppositely, in the $\mathrm{\Lambda }\mathrm{CDM}$ context, the situation is aggravated. For the considered large dataset, the discrepancy of best-fit values persists in both $({\sigma }_8-{\mathrm{\Omega }}_m)$ and $(h-{\mathrm{\Omega }}_m)$ planes and reinforces the mismatch of the Hubble parameter in CMB and BAO probes.

In this work, we study the lepton-number-violating processes of $K^{\pm }$ and $D^{\pm }$ mesons. Two quasidegenerate sterile neutrinos are assumed to induce such processes. Different from the case where only one sterile neutrino is involved, here, the $CP$ phases of the mixing parameters could give a sizable contribution. This, in turn, would affect the absolute values of the mixing parameters determined by the experimental upper limits of the branching fractions. A general function which expresses the difference between the mixing parameters for two-generation and one-generation cases is presented. Special cases with specific relations of the parameters are discussed. Besides, we also thoroughly investigate the $CP$ violation effect of such processes. It is shown that generally ${\mathcal{A}}_{CP}$ is a function of the sterile neutrino mass.

Measurements of the lifetime of neutrons trapped in a bottle have been consistently shorter than the lifetime measured in neutron beam experiments. With trapping potentials as low as 50 neV and neutron detectors located only at the top of the bottle, this discrepancy could be the result of the soft scattering of dark matter with neutrons. However, it is challenging to obtain the observed loss rate in conventional models of dark matter scattering. We show that this phenomenology is possible in composite models of dark matter where the soft scattering is from dark matter that has been captured and accumulated in the Earth. This solution can be tested by placing more neutron detectors around the trap, providing better angular coverage. The phenomenology of soft scattering by trapped composite dark matter is generic and suggests new experimental directions that could be pursued to detect this large class of models.

Light fermions that arise as composite states in confining gauge theories are stable due to fermion number conservation. This leads to dark matter (DM) candidates that behave similarly to elementary DM but where the cosmological stability arises automatically from the accidental symmetries of the theory. We present explicit models based on ’t Hooft anomaly matching conditions where DM is charged under the SM. For example an SU(N) gauge theory with fermions in the adjoint rep and triplet of ${\mathrm{SU}(2)}_L$ gives rise to DM made of multiple “Wino” triplets, while SO(N) gauge theories with $N_F=N-4$ flavors produce neutralinolike systems or SM quintuplets. Compositeness effects are crucial to determine the phenomenology.

We identify a parametrically light dilaton by studying the perturbations of metastable vacua along a branch of regular supergravity backgrounds that are dual to four-dimensional confining field theories. The branch includes also stable and unstable solutions. The former encompass, as a special case, the geometry proposed by Witten as a holographic model of confinement. The latter approach a supersymmetric solution, by enhancing a condensate in the dual field theory. A phase transition separates the space of stable backgrounds from the metastable ones. In proximity of the phase transition, one of the lightest scalar states inherits some of the properties of the dilaton, despite not being particularly light.

Black hole (BH) solution in the conformal Weyl gravity is a generalization of the Schwarzschild spacetime which includes two additional constants appearing when integrating the third order differential equations for gravitational field. One constant looks like the effective cosmological constant providing the de Sitter asymptotic of the solution. The other constant allows one to describe flat rotation of galaxies without introducing of the dark matter. Here we show that the effective “dark matter” term in the metric function drastically changes the asymptotic behavior of the evolution of the wave function of a scalar field: after the Schwarzschild-like ringing phase, the ringing at another, non-Schwarzschildian, longer-lived frequency takes place before the beginning of the exponential asymptotic tail. Thus the evolution of the scalar field consists of the three qualitatively different stages: the Schwarzschild-like ringing phase, the effective dark matter ringing phase and the de Sitter phase characterized by exponential tails. The late-time behavior of the electromagnetic field is qualitatively different as well: the exponential tails appear even in the absence of the effective de Sitter term.

In this work we investigate the hadronic effects on the $X_{J=0,1}(2900)$ states in heavy-ion collisions. We make use of effective Lagrangians to estimate the cross sections and their thermal averages of the processes $X_J\pi \to {\overline{D}}^{*}K,K^{*}\overline{D}$, as well as those of the corresponding inverse processes, considering also the possibility of different isospin assignments ($I=0$, 1). We complete the analysis by solving the rate equation to follow the time evolution of the $X_J(2900)$ multiplicities and determine how they are affected by the considered reactions during the expansion of the hadronic matter. We also perform a comparison of the $X_J(2900)$ abundances considering them as hadronic molecular states ($J=0$ as a $S$ wave and $J=1$ as a $P$ wave) and tetraquark states at kinetic freeze-out.

We present the formalism for connecting a second-order electroweak $2\stackrel{H_I+H_I}{\to }2$ transition amplitudes in the finite volume (with two hadrons in the initial and final states) to the physical amplitudes in the infinite volume. Our study mainly focuses on the case where the low-lying intermediate state consists of two scattering hadrons. As a side product, we also reproduce the finite-volume formula for $2\stackrel{H_I}{\to }2$ transition, originally obtained by Briceño and Hansen [Phys. Rev. D 94, 013008 (2016)]. With the available finite-volume formalism, we further discuss how to treat with the finite-volume problem in the double beta decays $nn\to ppee\overline{\nu }\overline{\nu }$ and $nn\to ppee$.

We calculate the spin-averaged amplitude for doubly virtual forward Compton scattering off nucleons in the framework of manifestly Lorentz-invariant baryon chiral perturbation theory at complete one-loop order $O(p^4)$. The calculations are carried out both in the infinite and in a finite volume. The obtained results allow for a detailed estimation of the finite-volume corrections to the amplitude which can be extracted on the lattice using the background field technique.

Inspired by the recent evidence of $P_{cs}(4459)$ reported by LHCb, we continue to perform the investigation of hidden-charm molecular pentaquarks with double strangeness, which are composed of an $S$-wave charmed baryon ${\mathrm{\Xi }}_c^{(\prime ,*)}$ and an $S$-wave anticharmed-strange meson ${\overline{D}}_s^{(*)}$. Both the $S\text{−}D$ wave mixing effect and the coupled channel effect are taken into account in realistic calculation. A dynamics calculation shows that there may exist two types of hidden-charm molecular pentaquark with double strangeness, i.e., the ${\mathrm{\Xi }}_c^{*}{\overline{D}}_s^{*}$ molecular state with $J^P=5/2^{-}$ and the ${\mathrm{\Xi }}_c^{\prime }{\overline{D}}_s^{*}$ molecular state with $J^P=3/2^{-}$. According to this result, we strongly suggest the experimental exploration of hidden-charm molecular pentaquarks with double strangeness. Facing such opportunity, obviously the LHCb will have great potential to hunt for them, with the data accumulation at Run III and after High-Luminosity-LHC upgrade.

We show how gravitational-wave observations of binary black hole (BBH) mergers can constrain the physical characteristics of a scalar field cloud parametrized by mass $\tilde{\mu }$ and strength ${\varphi }_0$ that may surround them. We numerically study the inspiraling equal-mass, nonspinning BBH systems dressed in such clouds, focusing especially on the gravitational-wave signals emitted by their merger-ringdown phase. These waveforms clearly reveal that larger values of $\tilde{\mu }$ or ${\varphi }_0$ cause bigger changes in the amplitude and frequency of the scalar-field-BBH ringdown signals. We show that the numerical waveforms of scalar-field-BBHs can be modeled as chirping sine-Gaussians, with matches in excess of 95%. This observation enables one to employ computationally expensive Bayesian studies for estimating the parameters of such binaries. Using our chirping sine-Gaussian signal model, we establish that observations of BBH mergers at a distance of 450 Mpc will allow to distinguish BBHs without any scalar field from those with a field strength ${\varphi }_0\gtrsim 5.5\times {10}^{-3}$, at any fixed value of $\tilde{\mu }\in [0.3,0.8]$, with 90% confidence or better, in single detectors with Advanced LIGO/Virgo type sensitivities. This provides hope for the possibility of determining or constraining the mass of ultralight bosons with gravitational-wave observations of BBH mergers.

We consider necessary and sufficient conditions for photons emitted from the vicinity of a Kerr black hole horizon to escape to infinity. The radial equation of motion determines necessary conditions for photons to reach infinity, and the polar angle equation of motion further restricts the allowed region of photon motion. Unlike emission from the equatorial plane, the latter restrictions are crucial for photon escape when the initial polar angle of the emission point is arbitrary. We provide a visualization tool to analyze these two conditions and demonstrate a procedure for revealing photon escape. Finally, we completely identify the two-dimensional impact parameter space in which photons can escape.

An important aspect of large-scale structure data analysis is the presence of non-negligible theoretical uncertainties, which become increasingly important on small scales. We show how to incorporate these uncertainties in realistic power spectrum likelihoods by an appropriate change of the fitting model and the covariance matrix. The inclusion of the theoretical error has several advantages over the standard practice of using the sharp momentum cut $k_{\max }$. First, the theoretical error covariance gradually suppresses the information from the short scales as the employed theoretical model becomes less reliable. This allows one to avoid laborious measurements of $k_{\max }$, which is an essential part of the standard methods. Second, the theoretical error likelihood gives unbiased constraints with reliable error bars that are not artificially shrunk due to overfitting. In realistic settings, the theoretical error likelihood yields essentially the same parameter constraints as the standard analysis with an appropriately selected $k_{\max }$, thereby effectively optimizing the choice of $k_{\max }$. We demonstrate these points using the large-volume $N$-body data for the clustering of matter and galaxies in real and redshift space. In passing, we validate the effective field theory description of the redshift space distortions and show that the use of the one-parameter phenomenological Gaussian damping model for fingers-of-God causes significant biases in parameter recovery.

Motivated by the swampland de Sitter conjecture, we consider a rolling scalar field as the source of dark energy. Furthermore, the swampland distance conjecture suggests that the rolling field will lead at late times to an exponentially light tower of states. Identifying this tower as residing in the dark sector suggests a natural coupling of the scalar field to the dark matter, leading to a continually reducing dark matter mass as the scalar field rolls in the recent cosmological epoch. The exponent in the distance conjecture $\tilde{c}$ is expected to be an $\mathcal{O}(1)$ number. Interestingly, when we include the local measurement of $H_0$, our model prefers a nonzero value of the coupling $\tilde{c}$ with a significance of $2.8\sigma$ and a best fit at $\tilde{c}\sim 0.3$. Modifying the recent evolution of the Universe in this way improves the fit to the data at the $2\sigma$ level compared to $\mathrm{\Lambda }$ cold dark matter. This string-inspired model automatically reduces cosmological tensions in the $H_0$ measurement as well as ${\sigma }_8$.

As an attractive candidate for dark matter, the primordial black holes (PBHs) in the mass range $(8\times {10}^{14}\sim {10}^{16})\mathrm{g}$ could be detected via their Hawking radiation, including neutrinos and antineutrinos of three flavors. In this paper, we investigate the possibility to constrain the PBHs as dark matter by measuring (anti)neutrino signals at the large liquid-scintillator detector of Jiangmen Underground Neutrino Observatory (JUNO). Among six available detection channels, the inverse beta decay ${\overline{\nu }}_e+p\to e^{+}+n$ is shown to be most sensitive to the fraction $f_{\mathrm{PBH}}$ of PBHs contributing to the dark matter abundance. Given the PBH mass $M_{\mathrm{PBH}}={10}^{15}\mathrm{g}$, we find that JUNO will be able to place an upper bound $f_{\mathrm{PBH}}\lesssim 3\times {10}^{-5}$, which is 20 times better than the current best limit $f_{\mathrm{PBH}}\lesssim 6\times {10}^{-4}$ from Super-Kamiokande. For heavier PBHs with a lower Hawking temperature, the (anti)neutrinos become less energetic, leading to a relatively weaker bound.

As part of the research on thermal noise reduction in gravitational-wave detectors, we experimentally demonstrate the conversion of a fundamental ${\mathrm{TEM}}_{00}$ laser mode at 1064 nm to higher-order Hermite-Gaussian modes (HG) of arbitrary order via a commercially available liquid crystal spatial light modulator. We particularly studied the ${\mathrm{HG}}_{5,5}/{\mathrm{HG}}_{10,10}/{\mathrm{HG}}_{15,15}$ modes. A two-mirror plano-spherical cavity filters the higher-order modes spatially. We analyze the cleaned modes via a three-mirror diagnosis cavity and measure a mode purity of $96/93/78\%$ and a conversion efficiency of $6.6\%/3.7\%/1.7\%$, respectively. A full set of simulations and mathematical proofs are also presented which shows that (i) Hermite-Gauss modes resonate in a two-mirror cavity provided mirrors are properly angled with respect to the impinging mode, and (ii) Hermite-Gauss modes resonate in triangular cavities. Hence, higher-order Hermite-Gauss modes are compatible with ground-based gravitational-wave detectors’ architecture and can be employed for the mitigation of mirror thermal noise for the third generation Einstein Telescope or Cosmic Explorer.