Skip Content
You are currently on the new version of our website. Access the old version .

Universe, Volume 9, Issue 11

2023 November - 30 articles

Cover Story: In this paper, we study analytical approximate solutions for second-order homogeneous differential equations with the existence of only two turning points (but without poles) by using the uniform asymptotic approximation (UAA) method. To be more concrete, we consider the Pöschl–Teller (PT) potential, for which analytical solutions are known. Depending on the values of the parameters involved in the PT potential, we find that the upper bounds of the errors of the approximate solutions in general are ≲0.15∼10% for the first-order approximation of the UAA method. The approximations can be easily extended to high orders, for which the errors are expected to be much smaller. Such obtained analytical solutions can be used to study cosmological perturbations in the framework of quantum cosmology as well as quasi-normal modes of black holes. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list .
  • You may sign up for email alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.

Articles (30)

  • Article
  • Open Access
2,084 Views
26 Pages

20 November 2023

After finding a solution for the Hayward regular black hole (HRBH) in massive gravity, we embed the (3+1)-dimensional HRBHs both in massless and in massive gravities into (5+2)- and (6+3)-dimensional Minkowski spacetimes, respectively. Here, massive...

  • Article
  • Open Access
9 Citations
2,060 Views
31 Pages

20 November 2023

In this work, we search for observational evidence of higher-order secular perturbations in three eclipsing binaries. These are slightly eccentric binaries, and they form the inner pairs of tight, compact, hierarchical triple star systems. Simultaneo...

  • Article
  • Open Access
6 Citations
2,014 Views
8 Pages

15 November 2023

We revisit the problem of constructing consistent interactions between a massive spin-3/2 field and a partially massless graviton in four-dimensional (anti) de Sitter (A)dS4 spacetime. We use the Stueckelberg formulation of the action principle for t...

  • Article
  • Open Access
3 Citations
1,790 Views
19 Pages

14 November 2023

In the framework of the Einstein–Dirac-aether theory we consider a phenomenological model of the spontaneous growth of the fermion number, which is triggered by the dynamic aether. The trigger version of spinorization of the early Universe is a...

  • Article
  • Open Access
2,216 Views
22 Pages

Molecular-Clump Detection Based on an Improved YOLOv5 Joint Density Peak Clustering

  • Jin-Bo Hu,
  • Yao Huang,
  • Sheng Zheng,
  • Zhi-Wei Chen,
  • Xiang-Yun Zeng,
  • Xiao-Yu Luo and
  • Chen Long

11 November 2023

The detection and analysis of molecular clumps can lead to a better understanding of star formation in the Milky Way. Herein, we present a molecular-clump-detection method based on improved YOLOv5 joint Density Peak Clustering (DPC). The method emplo...

  • Article
  • Open Access
2,237 Views
20 Pages

Why Are Some Radio Galaxies Detected by Fermi, but Others Not?

  • Danyi Huang,
  • Xuhong Ye,
  • Xiao Ye,
  • Xiulin Huang,
  • Yanjun Qian,
  • Ziyan Li,
  • Chengfeng Li,
  • Jiru Liao,
  • Hengji Zhang and
  • Junhui Fan
  • + 2 authors

8 November 2023

Aiming to answer an interesting question on why some radio sources can be detected by Fermi-LAT but others cannot, we compare several parameters of Fermi-detected Fanaroff-Riley radio galaxies (FFRs) and non-Fermi-detected sources (NFFRs), including...

  • Article
  • Open Access
4 Citations
2,350 Views
19 Pages

Dark Matter in Fractional Gravity III: Dwarf Galaxies Kinematics

  • Francesco Benetti,
  • Andrea Lapi,
  • Giovanni Gandolfi,
  • Minahil Adil Butt,
  • Yacer Boumechta,
  • Balakrishna S. Haridasu and
  • Carlo Baccigalupi

8 November 2023

Recently, we put forward a framework where the dark matter (DM) component within virialized halos is subject to a non-local interaction originated by fractional gravity (FG) effects. In previous works, we demonstrated that such a framework can substa...

  • Article
  • Open Access
4 Citations
2,111 Views
22 Pages

Automatic Classification of Spectra with IEF-SCNN

  • Jingjing Wu,
  • Yanxia Zhang,
  • Meixia Qu,
  • Bin Jiang and
  • Wenyu Wang

8 November 2023

Telescopes such as the Large Sky Area Multi-Object Spectroscopic Telescope and the Sloan Digital Sky Survey have produced an extensive collection of spectra, challenging the feasibility of manual classification in terms of accuracy and efficiency. To...

  • Article
  • Open Access
2 Citations
3,068 Views
18 Pages

Vacuum Energy, the Casimir Effect, and Newton’s Non-Constant

  • Benjamin Koch,
  • Christian Käding,
  • Mario Pitschmann and
  • René I. P. Sedmik

8 November 2023

The idea of quantum mechanical vacuum energy contributing to the cosmological vacuum energy density is not new. However, despite the persisting cosmological constant problem, few investigations have focused on this subject. We explore the possibility...

  • Article
  • Open Access
2 Citations
2,980 Views
18 Pages

Statistical and Radio Analysis of Exoplanets and Their Host Stars

  • Baoda Li,
  • Liyun Zhang,
  • Tianhao Su,
  • Xianming L. Han,
  • Prabhakar Misra and
  • Liu Long

8 November 2023

As of February 2022, over 4900 exoplanets have been confirmed. In this study, we conducted statistical analyses on both the exoplanets and their host stars’ parameters. Our findings suggest that the radius and true mass distribution of the exop...

  • Article
  • Open Access
2 Citations
2,294 Views
19 Pages

Ionospheric Response on Solar Flares through Machine Learning Modeling

  • Filip Arnaut,
  • Aleksandra Kolarski,
  • Vladimir A. Srećković and
  • Zoran Mijić

7 November 2023

Following solar flares (SF), the abrupt increase in X-radiation and EUV emission generates additional ionization and higher absorption of, e.g., electromagnetic waves in the sunlit hemisphere of the Earth’s ionosphere. The modeling of the ionos...

  • Article
  • Open Access
5 Citations
3,108 Views
10 Pages

How Long Does the Hydrogen Atom Live?

  • David McKeen and
  • Maxim Pospelov

4 November 2023

It is possible that the proton is stable while atomic hydrogen is not. This is the case in models with new particles carrying baryon number which are light enough to be stable themselves, but heavy enough so that proton decay is kinematically blocked...

  • Article
  • Open Access
8 Citations
2,522 Views
25 Pages

Neutrino Mixing Sum Rules and the Littlest Seesaw

  • Francesco Costa and
  • Stephen F. King

31 October 2023

In this work, we study the neutrino mixing sum rules arising from discrete symmetries and the class of Littlest Seesaw (LS) neutrino models. These symmetry-based approaches all offer predictions for the cosine of the leptonic CP phase cosδ...

  • Article
  • Open Access
4 Citations
2,589 Views
26 Pages

Uniform Asymptotic Approximation Method with Pöschl–Teller Potential

  • Rui Pan,
  • John Joseph Marchetta,
  • Jamal Saeed,
  • Gerald Cleaver,
  • Bao-Fei Li,
  • Anzhong Wang and
  • Tao Zhu

31 October 2023

In this paper, we study analytical approximate solutions for second-order homogeneous differential equations with the existence of only two turning points (but without poles) by using the uniform asymptotic approximation (UAA) method. To be more conc...

  • Review
  • Open Access
1 Citations
2,263 Views
26 Pages

31 October 2023

A review of the basic Hansen’s ideal frame algorithms for accurate numerical integration of perturbed elliptic motion is carried out. The fundamental approaches rely on the use of nonsingular variables and differ in the ways in which the ellips...

  • Article
  • Open Access
2 Citations
2,654 Views
14 Pages

31 October 2023

The unimodular theory of gravity is an alternative perspective to the traditional general relativity of Einstein and opens new possibilities for exploring its implications in cosmology. In this paper, we investigated Unimodular Gravity (UG) with the...

  • Article
  • Open Access
3 Citations
2,582 Views
16 Pages

A Meteor Detection Algorithm for GWAC System

  • Yicong Chen,
  • Guangwei Li,
  • Cuixiang Liu,
  • Bo Qiu,
  • Qianqian Shan and
  • Mengyao Li

30 October 2023

Compared with the international meteor surveillance systems, the ground wide angle camera (GWAC) system exhibits characteristics such as images with the resolution of 4K × 4K and single-site observation. These characteristics present challenges...

  • Article
  • Open Access
8 Citations
3,837 Views
15 Pages

30 October 2023

The recently obtained special Buchdahl-inspired metric Phys. Rev. D 107, 104008 (2023) describes asymptotically flat spacetimes in pure Ricci-squared gravity. The metric depends on a new (Buchdahl) parameter k˜ of higher-derivative characterist...

  • Review
  • Open Access
7 Citations
2,287 Views
16 Pages

30 October 2023

Impulsive solar energetic-particle (SEP) events were first distinguished as the streaming electrons that produce type III radio bursts as distinct from shock-induced type II bursts. They were then observed as the surprisingly enhanced 3He-rich SEP ev...

  • Article
  • Open Access
11 Citations
6,151 Views
21 Pages

Possible Wormholes in a Friedmann Universe

  • Kirill A. Bronnikov,
  • Pavel E. Kashargin and
  • Sergey V. Sushkov

29 October 2023

We study the properties of evolving wormholes able to exist in a closed Friedmann dust-filled universe and described by a particular branch of the well-known Lemaître–Tolman–Bondi solution to the Einstein equations and its generaliz...

  • Article
  • Open Access
1 Citations
2,565 Views
21 Pages

28 October 2023

Core-collapse supernovae (SNe) are one of the most powerful cosmic sources of neutrinos, with energies of several MeV. The emission of neutrinos and antineutrinos of all flavors carries away the gravitational binding energy of the compact remnant and...

  • Article
  • Open Access
1 Citations
2,651 Views
17 Pages

28 October 2023

The transiting planet K2-18 b is one of the best candidates for a relatively nearby world harboring biological life. The long-term orbital evolution of this planet is investigated using theoretical and purely numerical techniques for two possible con...

  • Article
  • Open Access
3 Citations
2,818 Views
13 Pages

27 October 2023

In search of physics beyond the standard model, new phenomena can be relevant in low energies. In view of the Standard Model Extension is an effective field theory, in this study we explore the fermionic sector by showing that the properties of nonre...

  • Review
  • Open Access
4 Citations
3,983 Views
27 Pages

27 October 2023

China has successfully carried out five lunar exploration missions since 2007. These missions indicate that China has successfully implemented a three-step lunar exploration program of “orbiting, landing, and returning”. Among them, the L...

  • Article
  • Open Access
1 Citations
2,004 Views
26 Pages

Hořava–Lifshitz F(R¯) Theories and the Swampland

  • Hugo García-Compeán,
  • Daniel Mata-Pacheco and
  • Luis Zapata

26 October 2023

The compatibility between the de Sitter Swampland conjecture and Hořava–Lifshitz F(R¯) theories with a flat FLRW metric is studied. We first study the standard f(R) theories and show that the only way in which the dS conjecture can be...

  • Article
  • Open Access
2 Citations
2,284 Views
19 Pages

Rapid Orbit-to-Orbit Transfer to Asteroid 4660 Nereus Using Solar Electric Propulsion

  • Alessandro A. Quarta,
  • Giovanni Mengali and
  • Marco Bassetto

26 October 2023

This paper analyzes the rapid rendezvous trajectory of a spacecraft equipped with an advanced solar electric propulsion system towards asteroid 4660 Nereus. In this context, a set of possible minimum-time orbit-to-orbit transfer trajectories is calcu...

  • Article
  • Open Access
1 Citations
1,727 Views
13 Pages

25 October 2023

The vanishing phase space generator of the full four-dimensional diffeomorphism-related symmetry group in the context of the Barbero–Immirz–Holst Lagrangian is derived directly, for the first time, from Noether’s second theorem. Its...

  • Article
  • Open Access
2 Citations
2,123 Views
15 Pages

NLTE Analysis of High-Resolution H-Band Spectra, V: Neutral Sodium

  • Zeming Zhou,
  • Jianrong Shi,
  • Shaolan Bi,
  • Hongliang Yan,
  • Junbo Zhang,
  • Kaike Pan and
  • Xiaodong Xu

25 October 2023

In order to derive sodium abundances and investigate the effects of non-local thermodynamic equilibrium (NLTE) on the formation of H-band Na I lines, we update the sodium atomic model by incorporating collision rates with hydrogen from new quantum-me...

Get Alerted

Add your email address to receive forthcoming issues of this journal.

XFacebookLinkedIn
Universe - ISSN 2218-1997