Universe, Volume 9, Issue 6

In this paper, we studied black string solutions under the consideration of rainbow gravity. We analytically obtained the solution for four-dimensional black strings in terms of the functions $f(E/E_p)$ and $g(E/E_p)$ that sets the energy scale where the r...

Thanks to the VIR spectrometer onboard NASA’s Dawn spacecraft, which orbited Vesta in 2011–2012, thousands of hyperspectral images of its surface have been collected. The mission confirmed the HED (Howardite–Eucrite–Diogenite)...

In this study, we analyzed the optical observations of a subluminous Type Ia supernova (SN Ia) 2017fzw, which exhibited high photospheric velocity (HV) at B-band maximum light. The absolute B-band peak magnitude was determined to be $M_{max}^B=-18.6$...

E-type $\alpha$-attractor models of single-field inflation were generalized further in order to accommodate production of primordial black holes (PBHs) via adding a near-inflection point to the inflaton scalar potential at smaller scales, in good agre...

The Hayabusa2 mission returned primitive samples from the C-type asteroid Ryugu to Earth. The C-type asteroids hold clues to the origin of Earth’s water and the building blocks of life. The rubble pile structure of C-type asteroids is a crucial...

We consider the propagation of electromagnetic waves in the Friedmann–Lemaître–Robertson–Walker metric. The exact solutions for plane and spherical wave are written down. The corresponding redshift, amplitude change, and dispe...

We investigate the structure of the medium formed in heavy ion collisions using three different models: the Color String Percolation Model (CSPM), the Core–Shell-Color String Percolation Model (CSCSPM), and the Color Glass Condensate (CGC) fram...

The results of experiments on the search for and study of double beta decay processes obtained over the past 5 years (from 2018 to April 2023) are discussed. The results of the search for neutrinoless double beta decay are presented, in which a sensi...

We investigate a holographic model for both spontaneous and explicit symmetry breaking of non-abelian flavour symmetries. This consists of a bottom-up model inspired by the top-down D3/probe D7-brane model. It incorporates the running anomalous dimen...

Although electrons (fermions)and photons (bosons) produce the same interference patterns in the two-slit experiments, known in optics for photons since the 17th Century, the description of these patterns for electrons and photons thus far was markedl...

Deep learning techniques are required for the analysis of synoptic (multi-band and multi-epoch) light curves in massive data of quasars, as expected from the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). In this follow-up study, w...

We conduct a detailed study of the electromagnetic field produced by a massive point particle undergoing hyperbolic (uniformly accelerated) motion in Minkowski space-time. Starting from the Liénard–Wiechert solution and using a covariant...

Electromagnetic (EM) observations and gravitational wave (GW) measurements enable us to determine the mass and radius of neutron stars (NSs) and their tidal deformability, respectively. These parameters offer valuable insights into the properties of...

In this paper, we discuss mechanical systems with inequality constraints $\mathsf{\Phi }(q,\dot{q},...)\le 0$. We demonstrate how such constraints can be taken into account by proper modification of the action which describes the original unconstrained dynamics...

In this paper, we consider homogeneous cosmological solutions in the context of the Weyl geometrical scalar–tensor theory. Firstly, we exhibit an anisotropic Kasner type solution taking advantage of some similarities between this theory and the...

We develop an action principle to construct the field equations for dissipative/resistive general relativistic two-temperature plasmas, including a neutrally charged component. The total action is a combination of four pieces: an action for a multifl...

When discussing the gauge symmetries of any theory, the Henneaux–Teitelboim transformations are often underappreciated or even completely ignored, due to their on-shell triviality. Nevertheless, these gauge transformations play an important rol...

In this work, we aim to characterize the effective scale height at the ionosphere F2-layer peak (H₀) by using in situ electron density (N_e) observations by Langmuir Probes (LPs) onboard the China Seismo-Electromagnetic Satellite (CSES—01). CSES...

Upcoming LIGO–Virgo–KAGRA (LVK) observational runs offer new opportunities to probe the central engines of extreme transient events. Cosmological gamma-ray bursts (GRBs) and core-collapse supernovae (CC-SNe), in particular, are believed t...

In this contribution to the Festschrift for Prof. Remo Ruffini, we investigate a formulation of quantum gravity using the Hořava–Lifshitz theory of gravity, which is General Relativity augmented by counter-terms to render the theory regula...

Radio astronomy uses radio telescopes to detect very faint emissions from celestial objects. However, human-made radio frequency interference (RFI) is currently a common problem faced by most terrestrial radio telescopes, and it is getting worse with...

In the QCD-like effective model, the Polyakov linear-sigma model, the isospin sigma field (${\overline{\sigma }}_3=f_{K^{\pm }}-f_{K^0}$) and the third generator of the matrix of the explicit symmetry breaking [$h_3=m_{a_0}^2\left(f_{K^{\pm }}-f_{K^0}\right)$] are estimated in ter...

The neutrino is perhaps the most elusive member of the particle zoo. The questions about its nature, namely: Dirac or Majorana, the value of its mass and the interactions with other particles, the number of its components including sterile species, a...

High quality nuclear data lie at the heart of accurately modelling stellar systems and terrestrial nuclear reactors. However, some key reaction cross sections have large uncertainties, which limit such models in predicting isotopic abundances and oth...

In this brief review, I summarize our basic knowledge about different types of isolated neutron stars. I discuss radio pulsars, central compact objects in supernova remnants, magnetars, nearby cooling neutron stars (also known as the magnificent seve...

Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions...

The purpose of this paper is to design tools that quantify the structure of the nonsymmetrical component of the solar magnetic field. With the Fourier transform and the machine learning identification of recurrent objects, we define the 27-day compon...

In this work, we present a study of ordinary muon capture (OMC) on ${}^{136}$Ba, the daughter nucleus of ${}^{136}$Xe double beta decay (DBD). The OMC rates at low-lying nuclear states (below 1 MeV of excitation energy) in ${}^{136}$Cs are assessed by using both the inte...

The Einsteinian theory of gravitation is among the best-established theories ever conceived in physics [...]

As with many fields from fashion to politics, science is susceptible to “bandwagon”-driven research where an idea becomes increasingly popular, garnering a growing amount of “scientific” support. Bandwagons allow scientists to...

Already in the cornerstone works on astrophysical black holes published as early as in the 1970s, Ruffini and collaborators have revealed the potential importance of an intricate interaction between the effects of strong gravitational and electromagn...

We propose a promising model of discrete spacetime based on nonassociative geometry and complex networks. Our approach treats space as a simplicial 3-complex (or complex network), built from “atoms” of spacetime and entangled states formi...

Inspired by the LHCb observation of hidden-charm pentaquarks, i.e., $P_c\left(4312\right)$, $P_c\left(4440\right)$, and $P_c\left(4457\right)$ in the $J/\psi p$ invariant mass spectrum, a calculation of the $J/\psi p$ scattering cross-section was performed using the quark-delocalization color sc...

In the description of transport phenomena, diffusion represents an important aspect. In certain cases, the diffusion may appear together with convection. In this paper, we study the diffusion equation with the self-similar Ansatz. With an appropriate...

The possibility of observing negative Shapiro-like gravitational time delay (or time advancement) due to the Earth’s gravity employing interferometric experiments on the Earth’s surface is discussed. It is suggested that such a measuremen...

A substantial body of phenomenological and theoretical work over the last few years strengthens the possibility that the vacuum energy density (VED) of the universe is dynamical, and in particular that it adopts the ‘running vacuum model’...

We propose the diagnostics of plasma parameters in flare loops using the data of multi-wavelength observations in both shrinkage and expansion phases of the loops. The approach of a flare loop as an equivalent electric circuit is applied. We show tha...

In this work, we investigate the existence of neutron stars (NS) in the framework of $f(\mathbb{T},\mathcal{T})$ gravity, where $\mathbb{T}$ is the torsion tensor and $\mathcal{T}$ is the trace of the energy–momentum tensor. The hydrostatic equilibrium equations are obtained, however, wi...

We analyze the expected arrival time spectrum of supernova neutrinos using simulated luminosity and compute the expected number of events in future detectors such as the DUNE Far Detector and Hyper-Kamiokande. We develop a general method using minimu...

Pulsating auroras are usually observed with ultralow-frequency (ULF) waves in the Pc 3–5 band (period 10–600 s). These auroras are thought to result from interactions between energetic electrons and chorus waves, but their relationship wi...

As known, the realistic, exponential, fall-off of the rate of production of light mesons in the chromo-electric field of a quark–antiquark string, as a function of the meson mass, can be obtained from the Schwinger-formula Gaussian fall-off wit...

The problem of quantum time and evolution of quantum systems, where time is not a parameter, is considered. In our model, following some earlier works, time is represented by a quantum operator. In this paper, similarly to the position operators in t...

Using an open thermodynamic systems theory, the effect of particle creation on the evolution and dynamics of the standard cosmological FLRW model in a higher-dimensional spacetime with functionally dependent cosmological and gravitational constants $\mathsf{\&}$...

Taking the generalized uncertainty principle (GUP) into account, we apply the corrected state density to investigate the entropy density, energy density, pressure and equation of state for the perfect relativistic gases of massless particles with an...

We consider the central configurations of the $1+N$-body problem, where N bodies are infinitesimal and the remaining one body is dominant. For regular polygon central configurations, we prove that the masses of all the infinitesimal bodies are equal wh...

Oort constants and local kinematics are vital parameters with which to study the structure and dynamics of the Milky Way. When GCNS was published, it provided a clean sample of stars in the solar vicinity, which gives us an ideal tool with which to d...

Fast Radio Bursts (FRBs) are millisecond-duration transient events that are typically observed at radio wavelengths and cosmological distances but their origin remains unclear. Furthermore, most FRB origin models are related to the processes at stell...

The black aurora is a distinct phenomenon characterized by spatially well-defined regions where the diffuse auroral luminosity decreases notably. Typically, black auroras present as arcs moving at lower velocities, patches with higher moving speeds,...

The theory of equatorward moving east-west elongated auroral arcs associated with field line resonance (FLR) has been proposed for decades. However, confirming this theory requires in-situ observations of FLR within the magnetosphere and simultaneous...

In this study, we aim to analyze the electromagnetic interference (EMI) regarding the Five-hundred-meter Aperture Spherical radio Telescope (FAST) caused by base stations in the International Mobile Telecommunications-2000 (IMT-2000) frequency band....