We investigate the condensation time of self-interacting axionlike particles in a gravitational well, extending the prior work [K. Kirkpatrick, A. E. Mirasola, and C. Prescod-Weinstein, Phys. Rev. D 102, 103012 (2020)] which showed that the Wigner formalism is a good analytic approach to describe a condensing scalar field. In the present work, we use this formalism to affirm that ${\varphi }^4$ self-interactions will take longer than necessary to support the time scales associated with structure formation, making gravity a necessary part of the process to bring axion dark matter into a solitonic form. Here we show that when the axions’ virial velocity is taken into account, the time scale associated with self-interactions will scale as ${\lambda }^2$. This is consistent with recent numerical estimates, and it confirms that the Wigner formalism described in prior work [K. Kirkpatrick, A. E. Mirasola, and C. Prescod-Weinstein, Phys. Rev. D 102, 103012 (2020)] is a helpful analytic framework to check computational work for potential numerical artifacts.

In this work we explore the effects that a possible primordial magnetic field can have on the inflaton effective potential, taking as the underlying model a warm inflation scenario, based on global supersymmetry with a new-inflation-type potential. The decay scheme for the inflaton field is a two-step process of radiation production, where the inflaton couples to heavy intermediate superfields, which in turn interact with light particles. In this context, we consider that both sectors, heavy and light, are charged and work in the strong magnetic field approximation for the light fields. We find an analytical expression for the one-loop effective potential, for an arbitrary magnetic field strength, and show that the trend of the magnetic contribution is to make the potential flatter in the origin’s vicinity, preserving the conditions for a successful inflationary process. This result is backed up by the behavior of slow-roll parameter $\epsilon$. The viability of this magnetic warm inflation scenario is also supported by the estimation of the effect of the magnetic field on the heavy particles decay width.

We perform maximum likelihood estimates for single and double flavor ultralight dark matter (ULDM) models using the Spitzer Photometry and Accurate Rotation Curves database. These estimates are compared to maximum likelihood estimates for several commonly used cold dark matter (CDM) models. By comparing various CDM models we find, in agreement with previous studies, that the Burkert and Einasto models tend to perform better than other commonly used CDM models. We focus on comparisons between the Einasto and ULDM models and analyze cases for which the ULDM particle masses are fixed or free to vary. For each of these analyses, we perform fits assuming the soliton and halo density profiles are summed together or matched at a given radius. Letting the particle masses vary and assuming the summed models, we find a negligible preference for any particular range of particle masses within ${10}^{-25}\mathrm{eV}\le m\le {10}^{-19}\mathrm{eV}$. For the matched models, we find that almost all galaxies prefer particle masses in the range ${10}^{-23}\mathrm{eV}\lesssim m\lesssim {10}^{-20}\mathrm{eV}$. For both double flavor models we find that most galaxies prefer approximately equal particle masses. Fixing the particle masses, we find the best fit results for the particle mass $m={10}^{-20.5}\mathrm{eV}$, assuming the single flavor models, and $m_1={10}^{-20.5}\mathrm{eV}$, $m_2={10}^{-20.2}\mathrm{eV}$, assuming the double flavor, matched model.

Redundant calibration is a technique in radio astronomy that allows calibration of radio arrays whose antennas lie on a lattice by exploiting the fact that redundant baselines should see the same sky signal. Because the number of measured visibilities scales quadratically with the number of antennas but the number of unknowns describing the individual antenna responses and the available information about the sky scales only linearly with the array size, the problem is always overconstrained as long as the array is big and dense enough. This is true even for nonlattice array configurations. In this work we study a generalized algorithm in which a per-antenna gain is replaced with a number of gains. We show that it can successfully fit data from an approximately redundant array on square lattice with pointing and geometry errors, but that the model’s parameters are difficult to link to the quantities of interest. We discuss the parametrization, limitations, and possible extensions of this algorithm.

We reanalyze the GW150914 postmerger data searching for quasinormal modes beyond the fundamental, quadrupolar mode. There is currently an ongoing disagreement in the literature about whether, and to what extent, the data contains evidence for a quasinormal mode overtone. We use a frequency-domain approach to ringdown data analysis that was recently proposed by the authors. Our analysis has several advantages compared to other analyses performed mainly in the time domain; in particular, the source sky position and the ringdown start time are marginalized over (as opposed to simply being fixed) as part of a Bayesian ringdown analysis. We find tentative evidence for an overtone in GW150914, but at a lower significance than reported elsewhere. Our preferred analysis, marginalizing over the uncertainty in the time of peak strain amplitude, gives a posterior on the overtone amplitude peaked away from zero at $\sim 1.8\sigma$.

We propose that weak scale leptogenesis via $\sim 10\mathrm{TeV}$ scale right-handed neutrinos could be possible if their couplings had transitory larger values in the early Universe. The requisite lifted parameters can be attained if a light scalar $\varphi$ is displaced a long distance from its origin by the thermal population of fermions $X$ that become massive before electroweak symmetry breaking. The fermion $X$ can be a viable dark matter candidate; for suitable choice of parameters, the light scalar itself can be dark matter through a misalignment mechanism. We find that a two-component dark matter population made up of both $X$ and $\varphi$ is a typical outcome in our framework.

It is a well-known fact that, in recent times, entanglement harvesting from the quantum field is being rigorously investigated further in flat and different curved backgrounds. The usually understood formulation studies the possibility of two uncorrelated Unruh-DeWitt detectors getting entangled over time due to the effects of quantum vacuum fluctuations. Our current work presents a thorough formulation to realize the entanglement harvesting from nonvacuum background fluctuations. In particular, we further consider single excitation field states and a pair of inertial detectors, respectively, in ($1+1$) and ($1+3$) dimensions for this investigation. Our main observation asserts that entanglement harvesting is suppressed compared to the vacuum fluctuations in this situation. Our other observations confirm a nonzero individual detector transition probability in this background and vanishing entanglement harvesting for parallel comoving detectors. We look into the characteristics of the harvested entanglement and discuss its dependence on different system parameters.

While the $1+\log$ slicing condition has been extremely successful in numerous numerical relativity simulations, it is also known to develop “gauge shocks” in some examples. Alternative “shock-avoiding” slicing conditions suggested by Alcubierre prevent these pathologies in those examples, but have not yet been explored and tested very broadly. In this paper we compare the performance of shock-avoiding slicing conditions with those of 1+log slicing for a number of “text-book” problems, including black holes and relativistic stars. While, in some simulations, the shock-avoiding slicing conditions feature some unusual properties and lead to more “gauge dynamics” than the $1+\log$ slicing condition, we find that they perform quite similarly in terms of stability and accuracy, and hence provide a very viable alternative to $1+\log$ slicing.

We present a novel calculation of the four-momentum that is radiated into gravitational waves during the scattering of two arbitrarily spinning bodies. Our result, which is accurate to leading order in $G$, to quadratic order in the spins, and to all orders in the velocity, is derived by using a Routhian-based worldline effective field theory formalism in concert with a battery of analytic techniques for evaluating loop integrals. While nonspinning binaries radiate momentum only along the direction of their relative velocity, we show that the inclusion of spins generically allows for momentum loss in all three spatial directions. We also verify that our expression for the radiated energy agrees with the overlapping terms from state-of-the-art calculations in post-Newtonian theory.

We study dark matter-helium scattering in the early Universe and its impact on constraints from cosmic microwave background (CMB) anisotropy measurements. We describe possible theoretical frameworks for dark matter-nucleon interactions via a scalar, pseudoscalar, or vector mediator; such interactions give rise to hydrogen and helium scattering, with cross sections that have a power-law dependence on relative velocity. Within these frameworks, we consider three scenarios: dark matter coupling to only neutrons, to only protons, and to neutrons and protons with equal strength. For these various cases, we use Planck 2018 temperature, polarization, and lensing anisotropy data to place constraints on dark matter scattering with hydrogen and/or helium for dark matter masses between 10 keV and 1 TeV. For any model that permits both helium and hydrogen scattering with a non-negative power-law velocity dependence, we find that helium scattering dominates the constraint for dark matter masses well above the proton mass. Furthermore, we place the first CMB constraints on dark matter that scatters dominantly/exclusively with helium in the early Universe.

We study a Friedmann-Lemaître-Robertson-Walker spacetime in the theory of $f(Q)$ gravity, where $Q$ denotes the nonmetricity scalar. It has been previously shown in the literature, that there exist four distinct families of connections, which are compatible with the isometries of the FLRW metric; three for the spatially-flat case and one when the spatial curvature is present. In the spatially-flat case, one connection is dynamically irrelevant and yields the dynamics of the coincident gauge in the Cartesian coordinates. For this, we obtain the general solution of an arbitrary $f(Q)$ theory with a perfect fluid-matter content, and present various examples for specific choices of the $f(Q)$ function. We proceed by studying the effect of the rest of the connections, which are dynamical and affect the equations of the motion. We concentrate in scenarios that depart from the $Q=\mathrm{const}$ case, which just reproduces General Relativity with a cosmological constant, and derive novel vacuum solutions for a power-law $f(Q)$ function.

By the reaction of kaon interacting with a proton, we investigate the production of the newly observed ${\eta }_1(1855)$ predicted in the picture of the $K{\overline{K}}_1(1400)$ molecular state and hybrid state. The total and differential cross sections of the concrete $K^{-}p\to {\eta }_1(1855)\mathrm{\Lambda }$ reaction are calculated. Taking the partial decay width of the ${\eta }_1$ to $K{\overline{K}}^{*}$ as 0.9 MeV and 98.1 MeV, the minimum cross section of the ${\eta }_1(1855)$ production via the $K^{-}p$ reaction can reach up 0.59 nb and 63.8 nb at the center of mass energies $W\simeq 3.5\mathrm{GeV}$, respectively. The differential cross sections for the ${\eta }_1(1855)$ production at the different center of mass energies are also available. Furthermore, we present the Dalitz processes of $2\to 3$ and $2\to 4$, and initially discuss the feasibility of finding out the ${\eta }_1(1855)$ in experiments like J-PARC.

In this work we perform a perturbative study of the Noether supercurrent operator in the context of supersymmetric $\mathcal{N}=1$ Yang-Mills theory on the lattice. The supercurrent mixes with several other operators, some of which are not gauge invariant, having the same quantum numbers. We determine, to one-loop order, the renormalization and all corresponding mixing coefficients by computing the relevant Green’s functions of each one of the mixing operators with external elementary fields. Our calculations are performed both in dimensional and lattice regularization. From the first regularization we obtain the $\overline{\mathrm{MS}}$-renormalized Green’s functions; comparison of the latter with the corresponding Green’s functions in the lattice regularization leads to the extraction of the lattice renormalization factors and mixing coefficients in the $\overline{\mathrm{MS}}$ scheme. The lattice calculations are performed to lowest order in the lattice spacing, using Wilson gluons and clover improved gluinos. The lattice results can be used in nonperturbative studies of supersymmetric Ward identities.

The scale of a coupling constant for rapidity-only evolution of transverse-momentum dependent (TMD) operators in the Sudakov kinematic region is calculated using the Brodsky-Lepage-Mackenzie optimal scale setting [S. J. Brodsky et al., Phys. Rev. D 28, 228 (1983).]. The effective argument of a coupling constant is halfway in the logarithmical scale between the transverse momentum and energy of TMD distribution. The resulting rapidity-only evolution equation is solved for quark and gluon TMDs.

In-hadron condensates, defined as the scalar form factors at zero-momentum transfer, are investigated for flavor-symmetric mesons in pseudoscalar and vector channels under the rainbow-ladder (RL) truncation within the Dyson-Schwinger equations framework. We confirm the efficiency of the in-hadron condensates in describing the effects of dynamical chiral symmetry breaking from both global and structural perspectives by comparing the meson masses, the dimensionless in-hadron condensates, and the partial wave decompositions of in-hadron condensates as functions of current-quark mass. From partial wave analysis, $\pi (1300)$ is inferred as a radial excitation dominated by $s$ waves, while $\rho (1450)$ needs further studies beyond the RL truncation. This work provides a new insight into the studies of hadron properties with partial wave analysis for the in-hadron condensates.

The DIRAC experiment at CERN investigated in the reaction $p(24\mathrm{GeV}/\mathrm{c})+Ni$ the particle pairs $K^{+}{K}^{-},{\pi }^{+}{\pi }^{-}$, and $p\overline{p}$ with relative momentum $Q$ in the pair system less than $100\mathrm{MeV}/\mathrm{c}$. Because of background influence studies, DIRAC explored three subsamples of $K^{+}{K}^{-}$ pairs, obtained by subtracting-using the time-of-flight (TOF) technique-the background from initial $Q$ distributions with $K^{+}{K}^{-}$ sample fractions more than 70%, 50%, and 30%. The corresponding pair distributions in $Q$ and in its longitudinal projection $Q_L$ were analyzed first in a Coulomb model, which takes into account only the Coulomb final-state interaction (FSI) and assuming pointlike pair production. This Coulomb model analysis leads to a $K^{+}{K}^{-}$ yield increase of about four at $Q_L=0.5\mathrm{MeV}/\mathrm{c}$ compared to $100\mathrm{MeV}/\mathrm{c}$. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering also strong FSI via the resonances $f_0(980)$ and $a_0(980)$ and a variable distance $r^{*}$ between the produced $K$ mesons besides Coulomb FSI. This analysis was based on three different parameter sets for the pair production. For the 70% subsample and with the best parameters, $3680\pm 370$ $K^{+}{K}^{-}$ pairs were found to be compared to $3900\pm 410$ $K^{+}{K}^{-}$ extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected $K^{+}{K}^{-}$ pairs was evaluated to be around $40000\pm 10\%$, which agrees with the result from the 30% subsample. The $K^{+}{K}^{-}$ pair number in the 50% subsample differs from the two other values by about three standard deviations, confirming—as discussed in the paper—that experimental data in this subsample is less reliable. In summary, the upgraded DIRAC experiment observed increased $K^{+}{K}^{-}$ production at small relative momentum $Q$. The pair distribution in $Q$ is well described by Coulomb FSI, whereas a potential influence from strong interaction in this $Q$ region is insignificant within experimental errors.

A foundational theorem due to Buchdahl states that, within general relativity (GR), the maximum compactness $\mathcal{C}\equiv GM/(R{c}^2)$ of a static, spherically symmetric, perfect fluid object of mass $M$ and radius $R$ is $\mathcal{C}=4/9$. As a corollary, there exists a compactness gap between perfect fluid stars and black holes (where $\mathcal{C}=1/2$). Here we generalize Buchdahl’s result by introducing the most general equation of state for elastic matter with constant longitudinal wave speeds and apply it to compute the maximum compactness of regular, self-gravitating objects in GR. We show that: (i) the maximum compactness grows monotonically with the longitudinal wave speed; (ii) elastic matter can exceed Buchdahl’s bound and reach the black hole compactness $\mathcal{C}=1/2$ continuously; (iii) however, imposing subluminal wave propagation lowers the maximum compactness bound to $\mathcal{C}\approx 0.462$, which we conjecture to be the maximum compactness of any static elastic object satisfying causality; (iv) imposing also radial stability further decreases the maximum compactness to $\mathcal{C}\approx 0.389$. Therefore, although anisotropies are often invoked as a mechanism for supporting horizonless ultracompact objects, we argue that the black hole compactness cannot be reached with physically reasonable matter within GR and that true black hole mimickers require either exotic matter or beyond-GR effects.

In the framework of gravothermal evolution of an ideal monatomic fluid, I examine the dynamical instability of the fluid sphere in ($N+1$) dimensions by exploiting Chandrasekhar’s criterion to each quasistatic equilibrium along the sequence of the evolution. Once the instability is triggered, it would probably collapse into a black hole if no other interaction halts the process. From this viewpoint, the privilege of ($3+1$)-dimensional spacetime is manifest, as it is the marginal dimensionality in which the ideal monatomic fluid is stable but not too stable. Moreover, it is the unique dimensionality that allows stable hydrostatic equilibrium with positive cosmological constant. While all higher dimensional ($N>3$) spheres are genuinely unstable. In contrast, in ($2+1$)-dimensional spacetime it is too stable either in the context of Newton’s theory of gravity or Einstein’s general relativity. It is well known that the role of negative cosmological constant is crucial to have the Bañados-Teitelboim-Zanelli (BTZ) black hole solution and the equilibrium configurations of a fluid disk. Owing to the negativeness of the cosmological constant, there is no unstable configuration for a homogeneous fluid disk to collapse into a naked singularity, which supports the cosmic censorship conjecture. However, BTZ holes of mass ${\mathcal{M}}_{\mathrm{BTZ}}>0$ could emerge from collapsing fluid disks. The implications of spacetime dimensionality are briefly discussed.

Emerging high-redshift cosmological probes, in particular quasars (QSOs), show a preference for larger matter densities, ${\mathrm{\Omega }}_m\approx 1$, within the flat $\mathrm{\Lambda }\mathrm{CDM}$ framework. Here, using the Risaliti-Lusso relation for standardizable QSOs, we demonstrate that the QSOs recover the same Planck-$\mathrm{\Lambda }\mathrm{CDM}$ universe as type Ia supernovae (SN), ${\mathrm{\Omega }}_m\approx 0.3$ at lower redshifts $0<z\lesssim 0.7$, before transitioning to an Einstein–de Sitter universe (${\mathrm{\Omega }}_m=1$) at higher redshifts $z\gtrsim 1$. We illustrate the same trend, namely increasing ${\mathrm{\Omega }}_m$ and decreasing $H_0$ with redshift, in SN but poor statistics prevent a definitive statement. We explain physically why the trend may be expected and show the intrinsic bias through non-Gaussian tails with mock SN data. Our results highlight an intrinsic bias in the flat $\mathrm{\Lambda }\mathrm{CDM}$ universe, whereby ${\mathrm{\Omega }}_m$ increases, $H_0$ decreases and $S_8$ increases with effective redshift, thus providing a new perspective on $\mathrm{\Lambda }\mathrm{CDM}$ tensions; even in a Planck-$\mathrm{\Lambda }\mathrm{CDM}$ universe the current tensions may be expected.

The conformal anomaly in curved spacetime with antisymmetric torsion is reconsidered, taking into account new important details. We formulate, for the first time, the covariant solution of the anomaly-induced effective action. The covariant effective action includes local terms corresponding to total derivatives in the conformal anomaly. The contribution of massless fermions to these terms is characterized by multiplicative anomaly, coming from two different choices of doubling for the spinor operator. On the other hand, the nonlocal part of anomaly-induced action is free of ambiguities and admits a low-energy limit, similar to the effective potential in the metric-scalar theory.