Astronomische Nachrichten最新文献

{"title":"Dark Energy From the Gravitational Wave Background With Scalar Field Dark Matter","authors":"Edwin L. Pérez-Ochoa,&nbsp;Tonatiuh Matos","doi":"10.1002/asna.70004","DOIUrl":"https://doi.org/10.1002/asna.70004","url":null,"abstract":"<p>Recent observational results, such as those from pulsar timing arrays (PTA), suggest a low-frequency Gravitational Wave Background (GWB) permeates our universe. This opens the possibility that gravitational waves could span a broader spectrum, potentially impacting cosmological scales. Among novel Dark Energy (DE) models that explain DE as a very low-frequency GWB, the Compton Mass Dark Energy model (CMaDE) has shown promising theoretical alignment with cosmic acceleration. In this study, we explore the cosmological implications of the CMaDE model when coupled with Scalar Field Dark Matter (SFDM) as the dark matter candidate. We numerically solve the cosmological evolution equations for this combined CMaDE+SFDM framework, examining its impact on key observables and comparing results to the standard <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ΛCDM</mi>\u0000 </mrow>\u0000 <annotation>$$ Lambda mathrm{CDM} $$</annotation>\u0000 </semantics></math> model. Our findings demonstrate that the CMaDE+SFDM model is broadly consistent with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ΛCDM</mi>\u0000 </mrow>\u0000 <annotation>$$ Lambda mathrm{CDM} $$</annotation>\u0000 </semantics></math>, showing similar evolution in observables such as the cosmic microwave background and the background energy densities, with some deviations that merit further investigation.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 3-4","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.70004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Quest for the Quark-Gluon Plasma From the Perspective of Dynamical Models of Relativistic Heavy-Ion Collisions","authors":"Marcus Bleicher,&nbsp;Elena Bratkovskaya","doi":"10.1002/asna.70006","DOIUrl":"https://doi.org/10.1002/asna.70006","url":null,"abstract":"<p>The physics of heavy-ion collisions is one of the most exciting and challenging directions of science for the last four decades. On the theoretical side one deals with a non-abelian field theory, while on the experimental side today's largest accelerators are needed to enable these studies. The discovery of a new stage of matter—called the quark-gluon plasma (QGP) - and the study of its properties is one of the major achievements of modern physics. In this contribution we briefly review the history of theoretical descriptions of heavy-ion collisions based on dynamical models, focusing on the personal experiences in this inspiring field.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 7-8","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.70006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glueball-Like Decay of X(1835) Into Two Photons","authors":"D. T. Da Silva,&nbsp;M. L. L. Da Silva","doi":"10.1002/asna.20250030","DOIUrl":"https://doi.org/10.1002/asna.20250030","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;The search for new states of matter has been the subject of study and research, as well as their identification in colliders, with exotic states being identified in experiments around the world in recent years. Among the possible exotic states provided in QCD we have the glueball, a bound state between gluons. Using a non-relativistic gluon bound state model, we calculate &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Γ&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mo&gt;→&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Gamma left(Gto gamma gamma right) $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, where &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ G $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is a pseudoscalar digluon (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {0}^{-+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), which is applied to a possible exotic state, the meson &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;X&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mn&gt;1835&lt;/mn&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ X(1835) $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. We start from the amplitudes, where we consider the process &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;→&lt;/mo&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ gamma gamma to {g}^{ast }{g}^{ast } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, with the &lt;i&gt;g&lt;/i&gt;*s being the massive constituent gluons and the amplitudes obtained in the lowest-order perturbative QCD deriving them from the QED calculation. The unknown parameters of the model such as the digluon wavefunction are obtained using experimentally measured values of the decay of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 ","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 3-4","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Slowly Pulsating Run-Away B Star at High Galactic Latitude Ejected From a Spiral Arm","authors":"Ulrich Heber,&nbsp;Maximilian Halenke,&nbsp;Aakash Bhat,&nbsp;Veronika Schaffenroth","doi":"10.1002/asna.70003","DOIUrl":"https://doi.org/10.1002/asna.70003","url":null,"abstract":"<p>We report the discovery of the young B6 V run-away star LAMOST J083323.18 + 430825.4, 2.5 kpc above the Galactic plane. Its atmospheric parameters and chemical composition are determined from LAMOST spectra, indicating normal composition. Effective temperature (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>T</mi>\u0000 <mi>eff</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {T}_{mathrm{eff}} $$</annotation>\u0000 </semantics></math> = <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>14,500</mn>\u0000 </mrow>\u0000 <annotation>$$ mathrm{14,500} $$</annotation>\u0000 </semantics></math> K) and gravity (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>log</mi>\u0000 <mi>g</mi>\u0000 </mrow>\u0000 <annotation>$$ log g $$</annotation>\u0000 </semantics></math> = <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>3.79</mn>\u0000 </mrow>\u0000 <annotation>$$ 3.79 $$</annotation>\u0000 </semantics></math>) suggest that the star is close to terminating hydrogen burning. An analysis of the spectral energy distribution allowed us to determine the angular diameter as well as the interstellar reddening. Using evolutionary models from the MIST database we derived the stellar mass (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>4.75</mn>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ 4.75{M}_{odot } $$</annotation>\u0000 </semantics></math>) and age (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mn>104</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>13</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>+</mo>\u0000 <mn>11</mn>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation>$$ {104}_{-13}^{+11} $$</annotation>\u0000 </semantics></math> Myr). The spectroscopic distance (4.17 kpc), the radius (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>4.5</mn>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mo>⊙</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ 4.5{R}_{odot } $$</annotation>\u0000 </semantics></math>), and the luminosity (<span></span><","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 5","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.70003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modified Field Equation With Gauss–Bonnet Gravity","authors":"Zhi-Fu Gao,&nbsp;Xin-Jun Zhao,&nbsp;Xiao-Feng Yang,&nbsp;Wen-Qi Ma,&nbsp;Zi-Rui Hu","doi":"10.1002/asna.20250027","DOIUrl":"https://doi.org/10.1002/asna.20250027","url":null,"abstract":"<div>\u0000 \u0000 <p>This work provides a comprehensive analysis of modifications to the Einstein–Hilbert action, with a particular focus on Gauss–Bonnet (GB) gravity, and addresses the theoretical challenges in unifying quantum gravity frameworks with the GB gravitational modifications. By developing a novel fourth-order tensor methodology to manage derivative couplings, we establish a stable framework that eliminates higher-order derivative instabilities while enabling modified gravitational phenomena. The model maintains consistency with low-energy string theory constraints and generates testable predictions for black hole thermodynamics and cosmic expansion dynamics. Our results reconcile discrepancies between modified gravity theories and quantum field theory requirements, providing new mathematical tools for analyzing high-energy gravitational interactions. This work bridges critical gaps between theoretical formulations and observational evidence in cosmology, offering a unified approach to modeling gravitational interactions across quantum and cosmological scales.</p>\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 7-8","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface to the 11th International Workshop on Astronomy and Relativistic Astrophysics (IWARA 2024)","authors":"César Augusto Zen Vasconcellos,&nbsp;Peter Hess,&nbsp;Fridolin Weber,&nbsp;Remo Ruffini,&nbsp;Jorge Horvath,&nbsp;Zhifu Gao,&nbsp;Dimiter Hadjimichef,&nbsp;Benno Bodmann","doi":"10.1002/asna.20250042","DOIUrl":"https://doi.org/10.1002/asna.20250042","url":null,"abstract":"<div>\u0000 \u0000 <p>This Conference Proceedings volume contains the written versions of most of the contributions presented during the 11th International Workshop on Astronomy and Relativistic Astrophysics (IWARA 2024). The Workshop took place in Machupicchu Pueblo (Aguas Calientes), Peru, from September 2–6, 2024. The Workshop provided a setting for discussing recent developments in a wide variety of topics, including Archaeoastronomy and Cognition, the Kerr metric and the Hawking temperature, Damour-Solodukhin-type Wormholes, Stellar Physics and General Relativity, Stochastic Quantum Mechanics in Curved Spaces, Gauss-Bonnet Theory, Quantum Gravity, Black Holes, Fast Radio Bursts, Neutron Stars, Strange Stars, X-ray Binaries, Pulsars, Gravitational Waves, and Dark Matter, among others. Most of these contributions are included in this volume.</p>\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 3-4","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetized Strange Stars and Gravitational Waves Signals","authors":"S. López-Pérez,&nbsp;D. Manreza-Paret,&nbsp;A. Pérez-Martínez,&nbsp;G. Gil-Pérez","doi":"10.1002/asna.20250041","DOIUrl":"https://doi.org/10.1002/asna.20250041","url":null,"abstract":"<div>\u0000 \u0000 <p>We investigate the emission of gravitational waves from spheroidal magnetized strange stars in two scenarios: an isolated, slowly rotating star and a binary system. For the isolated star, we compute the quadrupole moment and the amplitude of the gravitational waves that may be emitted. In the case of the binary system, we determine the tidal deformation by simultaneously solving the spheroidal structure equations and the Love number equation. Our results are compared with data inferred from the GW170817 event, which is also used to estimate the mass and tidal deformation of the companion star in the binary system. Our model supports the existence of binary systems formed by magnetized strange stars, predicting gravitational wave signals consistent with other models of binary systems composed of magnetized hadronic stars or non-magnetized quark stars.</p>\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 3-4","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the Spin of MAXI J1820+070 From Soft State by Insight-HXMT","authors":"Chun-Xiang Liao,&nbsp;Chao Huang,&nbsp;Jian-Chao Feng,&nbsp;Ai-Jun Dong","doi":"10.1002/asna.20250021","DOIUrl":"https://doi.org/10.1002/asna.20250021","url":null,"abstract":"<div>\u0000 \u0000 <p>MAXI J1820+070, discovered by the Monitor of All-sky X-ray Image (MAXI) in 2018, is a well-known black hole X-ray binary. This study presents a detailed spectral analysis using 2018 observations from the Insight Hard X-ray Modulation Telescope (HXMT). We explored the evolution of the Fe line shape and found it stable at 6.4 keV in the high/soft state, indicating the inner radius of the accretion disk remains at the Innermost Stable Circular Orbit. Additionally, we estimated the black hole spin (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>a</mi>\u0000 <mo>*</mo>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {a}_{ast } $$</annotation>\u0000 </semantics></math>) using the continuum fitting method, obtaining a spin of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>a</mi>\u0000 <mo>*</mo>\u0000 </msub>\u0000 <msubsup>\u0000 <mrow>\u0000 <mo>=</mo>\u0000 <mn>0.122</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>0.016</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>+</mo>\u0000 <mn>0.013</mn>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation>$$ {a}_{ast }={0.122}_{-0.016}^{+0.013} $$</annotation>\u0000 </semantics></math>, consistent with previous results. Through these findings, this study has contributed to the spectral analysis and spin parameter estimation of black hole X-ray binary systems, offering valuable insights into black hole behavior and its role in cosmology.</p>\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 7-8","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gauss–Bonnet Theory and Applications in Cosmology","authors":"Zirui Hu,&nbsp;Zhifu Gao,&nbsp;Cixing Chen,&nbsp;Luiz Carlos Garcia de Andrade,&nbsp;Cesar Augusto Zen Vasconcellos","doi":"10.1002/asna.20250029","DOIUrl":"https://doi.org/10.1002/asna.20250029","url":null,"abstract":"<div>\u0000 \u0000 <p>This review provides a comprehensive discussion of Gauss–Bonnet (GB) gravity, a gravitational theory incorporating higher-order curvature corrections, which can influence gravitational dynamics in higher dimensions. We explore the fundamental motivation for introducing the GB term, particularly in the context of high-energy physics and string theory-inspired scenarios, highlighting its potential in addressing key issues such as singularities, the nature of dark energy, cosmic acceleration, modifications to neutron stars and black holes, and cosmological singularities. Furthermore, we examine emerging research directions and recent advancements in the field, including torsion effects, compact astrophysical phenomena, and modified Gauss–Bonnet models, which further expand the applications of GB gravity in modern theoretical physics and cosmology.</p>\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 7-8","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Lens Mass in the Einstein Ring JWST-ER1","authors":"Fulvio Melia","doi":"10.1002/asna.20240144","DOIUrl":"https://doi.org/10.1002/asna.20240144","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;JWST has made several surprising discoveries, underscored by the “too early” appearance of well-formed galaxies and supermassive black holes. It recently also uncovered a compact galaxy (JWST-ER1g) associated with a complete Einstein ring (JWST-ER1r) at photometric redshift &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mi&gt;l&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;1.94&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;0.17&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mn&gt;0.13&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {z}_l={1.94}_{-0.17}^{+0.13} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, produced by a lensed galaxy at &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;2.98&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;0.47&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mn&gt;0.42&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {z}_s={2.98}_{-0.47}^{+0.42} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. In two independent studies, this system (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mtext&gt;lens&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;mn&gt;6.5&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mn&gt;11&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;⊙&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {M}_{mathrm{lens}}sim 6.5times {10}^{11}kern0.5em {M}_{odot } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) has yielded different conclusions concerning whether or not it requires an unexpected contribution of mass from sources other than stars and fiducial dark matter. The different redshift inferred by these two analysis for the lensed galaxy appears to be the culprit. In this paper, we examine the impact of the background cosmology on our interpretation of the JWST data. We compare the measured c","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 5","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}