Universe, Volume 12, Issue 2

This review presents a unified account of the NA35, NA49, and NA61/SHINE experiments, which together form a continuous programme of heavy-ion studies conducted at the H2 beamline of the CERN North Area using the SPS accelerator. The programme, spanni...

It has been reported that quantum correction modifies the topological charges of Anti-de-Sitter Reissner–Nordström (AdS-RN) black holes in Kiselev spacetime, yielding new perspectives on topological classification. This leads us to focus o...

We perform a systematic analysis of the nuclear dependence of two-particle–two-hole meson-exchange current contributions to inclusive lepton-nucleus scattering within the relativistic mean-field framework. We present microscopic calculations of...

We present a detailed study on the geometrization of the Proca field in the so-called Weyl Gauge-Invariant Theory, shedding new light on the physical interpretation of the Weyl field. We first describe the field equations of the theory. We then obtai...

This study presents U-Net deep learning of total electron content (TEC) obtained from Global Ionosphere Maps (GIMs) to forecast ionospheric TEC over the African 0–40° N latitude sector during geomagnetic storms which have occurred between 2...

We present archival photometry from the Gravitational-wave Optical Transient Observer (GOTO) for four Galactic novae discovered between 2017 and 2024, spanning some of the faintest ZTF24aaomlxy and PGIR22akgylf (at a marginal near-limit level consist...

We present a stereoscopic analysis of coronal streamer deflection induced by a CME-driven shock, utilizing multi-viewpoint coronagraph observations from STEREO-Ahead, STEREO-Behind, and SOHO. Driven by the continuous impact of the shock, the streamer...

In this study, we extract a 7-day binned $\gamma$-ray light curve from 2008 August to 2019 March in the energy range 0.1–300 GeV and identify four outburst periods with peak flux of >8.0$\times {10}^{-7}$ ph ${\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$. Four act...

Sporadic E (Es) layers exhibit strong intermittency and highly skewed intensity distributions, exerting significant impacts on high-frequency communication and navigation systems and posing challenges for data-driven prediction. Conventional single-s...

In this work, we investigate massive charged scalar perturbations in the background of three-dimensional dilaton black holes with a cosmological constant. We demonstrate that the wave equations governing the dynamics of these perturbations are exactl...

Theories of flavor operate at various scales. Recently it has been pointed out that in the context of modular flavor symmetries, certain combinations of observables are highly constrained, or even uniquely fixed, by modular invariance and holomorphic...

We investigated how a magnetic topological defect affects the vacuum polarization of a charged massive scalar field in a flat $(3+1)$-dimensional space-time. The defect was modeled as an impenetrable-to-matter-field, finite-thickness tube with magnetic...

The existence of dark matter is supported by multiple astrophysical observations, yet its particle nature remains unknown. The development of gravitational wave astronomy, especially with future space-based detectors such as LISA, provides new opport...

The spatially homogeneous perfect fluid solutions by Kompanneets–Chernov–Kantowski–Sachs are interpreted as a thermodynamic perfect fluid in isentropic evolution, namely, the isentropic limit of their non-homogeneous generalizations...

We develop a fully gauge-invariant analysis of gravitational-wave polarizations in metric $f\left(R\right)$ gravity with a particular focus on the modified Starobinsky model $f\left(R\right)=R+\alpha R^2-2\mathsf{\Lambda }$, whose constant-curvature solution $R_d=4\mathsf{\Lambda }$ provides...

To address image degradation in optical telescopes with fast focal ratios—a problem caused by the misalignment of optical elements during assembly and observation—this study proposes a high-precision calibration method for image quality d...

The Planet Nine hypothesis encompasses a body of about 5–8 Earth’s masses whose orbital plane would be inclined to the ecliptic by one or two tens of degrees and whose perihelion distance would be as large as about 240–385 astronomi...

During a period of intense solar activity and highly disturbed geomagnetic conditions, a large Forbush decrease began on 10 May 2024 accompanied by a historic geomagnetic storm that lasted for four days. This extreme geomagnetic disturbance classifie...

We present a panoramic view of several scaling relations (ScRs) of galaxies of different morphology. The ScRs are obtained from the data of two large surveys (WINGS and MANGA). We analyze the distribution (parameterized by the percent over the total)...

We investigate the impact of the vortex state of ultralight dark matter (ULDM) on the dynamical friction acting on moving globular clusters. Comparing this force with that for the solitonic ground state, it is shown that the internal structure and ro...

We present a study of the linear polarization properties of radio sources within the 10 deg². Wide Chandra Deep Field South (W-CDFS) in S-band (2–4 GHz). Our W-CDFS image has an angular resolution of 15 arcsec and a 1$\sigma$ RMS in Stokes I of...

In this study, we investigate temperature fluctuations in hot QCD matter using a three-flavor Polyakov loop-extended Nambu–Jona-Lasinio (PNJL) model. The high-order cumulant ratios $R_{n2}$ ($n>2$) exhibit non-monotonic variations across the chiral...

With the progressive release of data from numerous sky surveys, humanity has entered the era of astronomical big data. Multi-wavelength, multi-method research is playing an increasingly crucial role. Binaries account for a substantial fraction of all...

We study the conditions under which momentum-space equal-time correlators of scalar fields are finite in flat space. We identify cases where these correlators can be divergent even after renormalization, and we provide sufficient criteria for their e...

Deep learning has emerged as a transformative methodology in modern cosmology, providing powerful tools to extract meaningful physical information from complex astronomical data. This paper implements a novel Bayesian graph deep learning framework fo...

We conjecture that during the time period preceding the inflationary epoch, the background matter was initially a condensate formed from a many-body system of indistinguishable particles whose states were in a quantum superposition. This resulted in...

We show that the Novikov coordinates can be obtained in a direct and physically transparent way from the radial geodesics of massive particles with negative energy in the Schwarzschild spacetime. These geodesics form a complete congruence that covers...

We present an advanced statistical framework for estimating the relative intensity of astrophysical event distributions (e.g., Gamma-Ray Bursts, GRBs) on the sky tofacilitate population studies and large-scale structure analysis. In contrast to the t...

The gravitational wave event GW190521 seems to be the only BH merger event possibly correlated with an electromagnetic counterpart, which appeared about 34 days after the GW event. This work aims to confirm that the electromagnetic bump towards the A...

A conceptual design study is presented for a hemispherical, two-chamber water Cherenkov detector instrumented with bladder-embedded light traps. The detector consists of a rigid aluminium vessel enclosing a water volume that is divided into an outer,...

This work investigates the differences between the monthly and 13-month smoothed sunspot numbers since 1749, using data from sunspot number (version 2). The distribution of the differences is centered near zero, with 74% of all values lying between &...