Universe, Volume 9, Issue 2

Analysis of transverse momentum distributions is a useful tool to understand the dynamics of relativistic particles produced in high-energy collisions. Finding a proper distribution function to approximate the spectra is a vastly developing area of r...

The equations of general relativity are recast in the form of a wave equation for the Weyl tensor. This allows reformulation of gravitational wave theory in terms of curvature waves, rather than metric waves. The existence of two transverse polarizat...

In Schwarzschild acoustic black hole (SABH) spacetime, we investigate the wave dynamics for the fermions. To this end, we first take into account the Dirac equation in the SABH by employing a null tetrad in the Newman–Penrose (NP) formalism. Th...

In this work, we interpret the newly observed ${\eta }_1\left(1855\right)$ resonance with exotic $J^{PC}=1^{-+}$ quantum numbers in the $I=0$ sector, reported by the BESIII Collaboration, as a dynamically generated state from the interaction between the lightest pseudos...

In the framework of the A Multi-Phase Transport (AMPT) model, the multi-particle azimuthal cumulant method is used to calculate the linear and mode-coupled contributions to the quadrangular flow harmonic ($v_4$) and the mode-coupled response coefficient...

Many new particles, mostly hadrons, are produced in high-energy collisions between atomic nuclei. The most popular models describing the hadron-production process are based on the creation, evolution and decay of resonances, strings or quark–gl...

The binary neutron star merger observed and localized on 17 August 2017 by the LIGO and Virgo gravitational interferometers and by numerous telescopes on the ground and in orbit linked in an unambiguous way the coalescence of double neutron stars wit...

We construct a holographic p-wave superconductor with excited states in the 4D Einstein–Gauss–Bonnet gravity using the Maxwell complex vector field model. In the probe limit, we observe that, the higher curvature correction or the higher...

Standard cosmology has long been plagued by a number of persistent problems. The origin of the apparent acceleration of the cosmic expansion remains enigmatic. The cosmological constant has been reintroduced as a free parameter with a value in energy...

In this study, the variability of the ionospheric total electron content (TEC) in the South Atlantic Anomaly (SAA) in the solar maximum of 2002 and the solar minimum of 2008 were compared by using an empirical orthogonal function (EOF) analysis. The...

Unfortunately, the Hamiltonian mechanics of degenerate Lagrangian systems is usually presented as a mere recipe of Dirac, with no explanation as to how it works. It then comes to discussing conjectures of whether all primary constraints correspond to...

We consider a cosmological model in the framework of Einstein–Cartan theory with a single scalar torsion $\varphi =\varphi \left(t\right)$ and reconstruct the torsion model corresponding to the holographic dark energy (HDE) density. By studying the correspondin...

Theoretical arguments and lattice simulations suggest that, beside the known resonance of mass $m_h=$ 125 GeV, the Higgs field could exhibit a second mass scale ${\left(M_H\right)}^{\mathrm{theor}}=690\pm 10\left(\mathrm{stat}\right)\pm 20\left(\mathrm{sys}\right)\mathrm{GeV}$. In spite of its large mass, the heavier sta...

Supernova Remnants (SNRs) are generally believed to produce the cosmic rays in our Galaxy due to the powerful supernova blast waves generated by expanding SNRs. In contrast to the leptonic cosmic-ray component that is clearly seen by the SNR emission...

The temperature dependence of the QCD string-breaking distance is evaluated in terms of the string tension and the rate of production of light mesons in the chromo-electric field of a flux tube. As a function of the meson mass, the mentioned rate can...

Terrestrial auroras are highly structured that visualize the perturbations of energetic particles and electromagnetic fields in Earth’s space environments. However, the identification of auroral morphologies is often subjective, which results i...

The transition from the large-amplitude rapidly-decaying regime of kink oscillations of plasma loops observed in the corona of the Sun to the low-amplitude decayless oscillations is modelled. In this study, the decayless regime is associated with the...

The $\Lambda$CDM model provides a good fit to most astronomical observations but harbors large areas of phenomenology and ignorance. With the improvements in the precision and number of observations, discrepancies between key cosmological parameters o...

Accurate measurements of the energy spectrum and anisotropy can help us discover local cosmic-ray accelerators. Our recent works have shown that spectral hardening above 200 GeV in the energy spectra and transition of large-scale anisotropy at ∼1...

Using the radio spectra of the 2 April 2022 eruptive flare, we analyze a group of highfrequency type III bursts by our new wavelet method. In this analysis, we found a multi-periodicity of these bursts that is interpreted by the electron beams accele...

Semi-empirical frameworks are widely used in calculating the bandhead energies of three-quasiparticle (3qp) configurations observed in well-deformed odd-A nuclei. In the present study, our aim is to improve the previous version of the semi-empirical...

We explore the potential of ultimate unification of the Standard Model matter and gauge sectors into a single $E_8$ superfield in ten dimensions via an intermediate Pati–Salam gauge theory. Through a consistent realisation of a ${\mathbb{T}}^6/({\mathbb{Z}}_6\times {\mathbb{Z}}_2\&tim$...

The concept of polaron quasiparticles was first introduced in the pioneering papers by Landau and Feynman in the 1930s and 1940s. It describes the phenomenon of an external particle producing a bound state in an embedded medium. Since then, the study...

In this paper, we investigate the thermal stability and thermodynamic geometries of non-rotating/rotating charged black holes. For these black holes, we apply barrow entropy to determine the physical quantities such as mass and temperature of the sys...

A new final endpoint of complete gravitational collapse is proposed. By extending the concept of Bose–Einstein condensation to gravitational systems, a static, spherically symmetric solution to Einstein’s equations is obtained, characteri...

Using the temperature data observed from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), we investigate the response of the mesosphere and lower thermosphere (MLT) to two medium geomagnetic storms with disparate durations,...

A possible solution of the problem of time in the Wheeler–DeWitt quantum geometrodynamics is that time appears within a semiclassical limit. Following this line of thinking, one can come to the Schrodinger equation for matter fields in curved s...

Results from photometry and high-resolution spectroscopy have demonstrated the existence of multiple populations in globular clusters, where one or more stellar generations of stars coexist with the original population. We study the possibility that...

We consider a scenario of large-scale modification of gravity that does not invoke extra degrees of freedom, but includes coupling between baryonic matter and dark matter in the Einstein frame. The total matter energy density follows the standard con...

Recently, persistent homology analysis has been used to investigate phase structure. In this study, we apply persistent homology analysis to the QCD effective model with heavy quarks at finite imaginary chemical potential; i.e., the Potts model with...

Wormholes are hypothetical space-time tunnels with nontrivial topologies capable of connecting either two distant regions of the same universe or two different universes [...]

We investigate natural inflation with non-minimal coupling to gravity, characterized either by a quadratic or a periodic term, within the warm inflation paradigm during the slow-roll stage, in both strong and weak dissipation limits; and show that, i...

Identification of small-scale auroral structures is key to searching for auroral events. However, it is impracticable for humans to manually select sufficient aurora events for statistical analysis, and it is also challenging for computers because of...

The Neil–Gehrels Swift Observatory has added extensively to our understanding of small bodies in our solar system through its capabilities to rapidly respond to short-live events such as outbursts and collisions, through its near-ultraviolet co...

In this work, we derive exact analytic formulae for the inner and outer surfaces representing the boundary of the ergoregion appearing in the Tomimatsu–Sato (TS) metric. Exact expressions for the radii of the ergoregion in prolate spheroidal co...

The next generation of cosmological observations are expected to improve the measurements of several quantities connected to the primordial inflation in the early Universe. These quantities include, for example, improved measurements for the spectral...

In this paper, we construct a solvable toy model of the quantum dynamics of the interior of a spherical black hole with falling spherical scalar field excitations. We first argue about how some aspects of the quantum gravity dynamics of realistic bla...

The Liquid Argon Time Projection Chamber (LAr-TPC) technology was conceived at the end of the 1970s as a way to combine the excellent spatial and calorimetric performance of the traditional bubble chambers with the electronic read-out of the TPCs, ob...

We consider the role of the torsion axial-vector played in the dynamics of the Dirac spinor fields: we show that the torsional correction entails effects that render regular the otherwise singular spinorial matter field distribution. Comments about c...

Within the framework of Einstein’s General Relativity we study strange quark stars assuming an interacting equation-of-state. Taking into account the presence of anisotropies in a sphere made of ultra dense matter, we employ the formalism based...

We consider the effect of a thermal bath on quantum correlations induced by the gravitational interaction in the weak field limit between two massive cat states, called gravitational cat (gravcat) states. The main goal of this paper is to provide a g...

Equations governing the evolution of a star involve multiple coupling constants. Thus, the time it spends as a main-sequence star can be expected to depend on whether or not such constants vary over the time scale of stellar evolution. When the star...

Among all the known particles in our Universe, neutrinos are definitely the most elusive and mysterious [...]

The secular dressed diffusion equation describes the long-term evolution of collisionless systems of particles with long-range interactions, such as self-gravitating systems submitted to a weak external stochastic perturbation. We successively consid...

In relativistic heavy-ion collisions, event-by-event fluctuations are known to have non-trivial implications. Even though the probability distribution is geometrically isotropic for the initial conditions, the anisotropic ${\epsilon }_n$ still differs fro...

New results on the radio-quiet type 2 quasar, known as the Teacup galaxy (SDSSJ1430+1339), based on the long-slit and 3D spectroscopic data obtained at the Russian 6-m telescope, are presented. The ionized gas giant nebula, which extends up to $r=56$ k...

In this article, we try to determine the conditions when a ghost field, in conjunction with a barotropic fluid, produces a stable accelerating expansion phase of the universe. It is seen that, in many cases, the ghost field produces a condensate and...

Closed timelike curves (CTCs) are non-intuitive theoretical solutions of general relativity field equations. The main paradox associated with the physical existence of CTCs, the so-called grandfather paradox, can be satisfactorily solved by a quantum...

The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein’s general relativity could alleviate the different problems associated with it that result from the inte...

The Standard Model (SM) of particle physics is the most general renormalizable theory which is built on a few general principles and fundamental symmetries with the given particle content. However, multiple symmetries are not built into the model and...