Fortschritte Der Physik-Progress of Physics最新文献

{"title":"The Chiral Ring of \u0000 \u0000 \u0000 D\u0000 =\u0000 4\u0000 \u0000 $D=4$\u0000 , \u0000 \u0000 \u0000 N\u0000 =\u0000 1\u0000 \u0000 ${mathcal {N}}=1$\u0000 SYM with Exceptional Gauge Groups","authors":"Martin Cederwall,&nbsp;Gabriele Ferretti","doi":"10.1002/prop.202400027","DOIUrl":"10.1002/prop.202400027","url":null,"abstract":"<p>The Cachazo–Douglas–Seiberg–Witten conjecture, concerning the algebraic structure of the chiral ring in <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>N</mi>\u0000 <mo>=</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <annotation>${mathcal {N}}=1$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>D</mi>\u0000 <mo>=</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 <annotation>$D=4$</annotation>\u0000 </semantics></math> supersymmetric Yang–Mills theory, is proven for exceptional gauge groups. This completes the proof of the conjecture.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 5","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.202400027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140156774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Krylov Complexity of Fermionic and Bosonic Gaussian States","authors":"Kiran Adhikari,&nbsp;Adwait Rijal,&nbsp;Ashok Kumar Aryal,&nbsp;Mausam Ghimire,&nbsp;Rajeev Singh,&nbsp;Christian Deppe","doi":"10.1002/prop.202400014","DOIUrl":"10.1002/prop.202400014","url":null,"abstract":"<p>The concept of <i>complexity</i> has become pivotal in multiple disciplines, including quantum information, where it serves as an alternative metric for gauging the chaotic evolution of a quantum state. This paper focuses on <i>Krylov complexity</i>, a specialized form of quantum complexity that offers an unambiguous and intrinsically meaningful assessment of the spread of a quantum state over all possible orthogonal bases. This study is situated in the context of Gaussian quantum states, which are fundamental to both Bosonic and Fermionic systems and can be fully described by a covariance matrix. While the covariance matrix is essential, it is insufficient alone for calculating Krylov complexity due to its lack of relative phase information is shown. The relative covariance matrix can provide an upper bound for Krylov complexity for Gaussian quantum states is suggested. The implications of Krylov complexity for theories proposing complexity as a candidate for holographic duality by computing Krylov complexity for the thermofield double States (TFD) and Dirac field are also explored.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 5","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140153091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Issue Information: Fortschritte der Physik 2 / 2024","authors":"","doi":"10.1002/prop.202400902","DOIUrl":"https://doi.org/10.1002/prop.202400902","url":null,"abstract":"","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.202400902","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140053041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Mass Gap of the Space-time and its Shape","authors":"Ahmed Farag Ali","doi":"10.1002/prop.202200210","DOIUrl":"10.1002/prop.202200210","url":null,"abstract":"<p>Snyder's quantum space-time which is Lorentz invariant is investigated. It is found that the quanta of space-time have a positive mass that is interpreted as a positive real mass gap of space-time. This mass gap is related to the minimal length of measurement which is provided by Snyder's algebra. Several reasons to consider the space-time quanta as a 24-cell are discussed. Geometric reasons include its self-duality property and its 24 vertices that may represent the standard model of elementary particles. The 24-cell symmetry group is the Weyl/Coxeter group of the <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>F</mi>\u0000 <mn>4</mn>\u0000 </msub>\u0000 <annotation>$F_4$</annotation>\u0000 </semantics></math> group which was found recently to generate the gauge group of the standard model. It is found that 24-cell may provide a geometric interpretation of the mass generation, Avogadro number, color confinement, and the flatness of the observable universe. The phenomenology and consistency with measurements is discussed.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140034343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Particle Dynamics and Matter Accretion onto Non-linear Charged AdS Black Holes in Massive Gravity","authors":"Adnan Malik,&nbsp;M. Umair Shahzad","doi":"10.1002/prop.202300116","DOIUrl":"10.1002/prop.202300116","url":null,"abstract":"<p>This article investigates the dynamics of charged particles and accretion process around nonlinear charged AdS black holes (BHs). the impact of key factors such as angular momentum, specific energy, and magnetic field on the behavior of particles are focused. Firstly, the concept of the effective potential is examined, which provides insights into the forces acting on particles and the escape velocity they must overcome. The innermost stable circular orbit (ISCO) is also discussed, which is the closest distance a particle can orbit a BH without being pulled in and explore the conditions for particle escape. Next, the energy efficiency and epicyclic frequency of test particles are studied, which measure the amount of energy particle loses due to friction and the frequency of its oscillations, respectively. The accretion processes is analyzed by examining the radial velocity, energy density, and accretion mass of matter falling into the BH. Using the equation of state, how different types of fluid, such as stiff, dust, quintessence and phantom-like dark energy fluid, affect the accretion process near a BH is investigated. Throughout this study, the parameter <span></span><math>\u0000 <semantics>\u0000 <mi>k</mi>\u0000 <annotation>$k$</annotation>\u0000 </semantics></math> plays a key role in shaping the dynamics of particles and accretion systems is found. This parameter <span></span><math>\u0000 <semantics>\u0000 <mi>k</mi>\u0000 <annotation>$k$</annotation>\u0000 </semantics></math> is a measure of the strength of the nonlinear electrodynamics field, and it can have a significant impact on the radius of the ISCO, the energy efficiency of accretion, and other properties. These findings provide new insights into the physics of particle dynamics around nonlinear charged AdS BHs. They could have implications for understanding the behavior of matter in extreme gravitational environments, such as those found near the center of galaxies.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139988221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"New Wormhole Solutions in Quadratic \u0000 \u0000 \u0000 f\u0000 (\u0000 Q\u0000 )\u0000 \u0000 $f(mathcal {Q})$\u0000 -Gravity Regime","authors":"Sweeti Kiroriwal,&nbsp;Jitendra Kumar,&nbsp;Sunil Kumar Maurya,&nbsp;Sourav Chaudhary,&nbsp;Abdul Aziz","doi":"10.1002/prop.202300197","DOIUrl":"10.1002/prop.202300197","url":null,"abstract":"<p>Nowadays, alternative gravity is a crucial tool for addressing some enduring observational problems, such as the dark universe. Additionally, they can be used to advance the results of general relativity in astrophysics. Wormholes, or imagined passageways through spacetime, have the potential to revolutionize interstellar transport and cosmic interconnection. In the present work, the existence and characteristics of wormhole solutions in the context of the non-linear function of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(mathcal {Q})$</annotation>\u0000 </semantics></math> gravity are investigated. A typical characteristic of maintaining wormholes is the presence of exotic stuff that defines the energy conditions (ECs). The authors looked at the ECs that must be met and analyzed how the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(mathcal {Q})$</annotation>\u0000 </semantics></math> function affects the energy-momentum requirements for maintaining the wormholes open. For a comprehensive understanding of wormhole geometries, we also studied the embedding diagram and volume integral quantifier.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139980340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Singularity-Free Charged Compact Star Model Under \u0000 \u0000 \u0000 F\u0000 (\u0000 Q\u0000 )\u0000 \u0000 $F(Q)$\u0000 -Gravity Regime","authors":"Sunil Kumar Maurya,&nbsp;Mahmood Khalid Jasim,&nbsp;Abdelghani Errehymy,&nbsp;Kottakkaran Sooppy Nisar,&nbsp;Mona Mahmoud,&nbsp;Riju Nag","doi":"10.1002/prop.202300229","DOIUrl":"10.1002/prop.202300229","url":null,"abstract":"&lt;p&gt;In this paper, the possibility of existing a novel class of compact charged spheres based on a charged perfect fluid within the realm of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;f&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;Q&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$f(Q)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; gravity theory is explored. The authors started by proposing physically meaningful explicit formulas for the potential, denoted &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;λ&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$lambda (r)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and the electric field to find a close-form solution. More precisely, the change of the dependent variable approach by exploiting the transformation &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Y&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;e&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;ζ&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$Y(r)=e^{zeta (r)/2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is applied. Successively, the field equations analytically are solved and generate the most general solution, which leads us to examine various significant aspects of the stellar system. These aspects comprise the regularity of gravitational potentials, energy density and pressure, electric charge, the mass-radius relationship, subluminal sound velocities in the radial direction, and the adiabatic index for charged compact stars. For a more in-depth system study, mass measurements using contour diagrams are carried out. This mainly involves varying the variable parameters &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;β&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$beta _1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$E_0$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; to distinguish their effect on the mass distribution within the stellar structure. What is more, the electric charge controls the stability of the stellar system is shown, which yields that a stable system can possess a maximum charg","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139980481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Asymptotically-Flat Black Hole Solutions in Symmergent Gravity","authors":"Beyhan Puliçe,&nbsp;Reggie C. Pantig,&nbsp;Ali Övgün,&nbsp;Durmuş Demir","doi":"10.1002/prop.202300138","DOIUrl":"10.1002/prop.202300138","url":null,"abstract":"<p>Symmergent gravity is an emergent gravity model with an <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 <mo>+</mo>\u0000 <msup>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$R+R^2$</annotation>\u0000 </semantics></math> curvature sector and an extended particle sector having new particles beyond the known ones. With constant scalar curvature, asymptotically flat black hole solutions are known to have no sensitivity to the quadratic curvature term (coefficient of <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <annotation>$R^2$</annotation>\u0000 </semantics></math>). With variable scalar curvature, however, asymptotically-flat symmergent black hole solutions turn out to explicitly depend on the quadratic curvature term. In the present work, asymptotically-flat symmergent black holes with variable scalar curvature are constructed and used its evaporation, shadow, and deflection angle to constrain the symmergent gravity parameters. Concerning their evaporation, new particles predicted by symmergent gravity are found, even if they do not interact with the known particles, can enhance the black hole evaporation rate. Concerning their shadow, statistically significant symmergent effects are reached at the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 <mspace></mspace>\u0000 <mi>σ</mi>\u0000 </mrow>\u0000 <annotation>$2,sigma$</annotation>\u0000 </semantics></math> level for the observational data of the Event Horizon Telescope (EHT) on the Sagittarius A* supermassive black hole are shown. Concerning their weak deflection angle, discernible features for the boson-fermion number differences are revealed, particularly at large impact parameters. These findings hold the potential to serve as theoretical predictions for future observations and investigations on black hole properties.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.202300138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139967688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"On the Generalized Lemaitre Tolman Bondi Metric: Classical Sensitivities and Quantum Einstein-Vaz Shells","authors":"Mohammadreza Molaei,&nbsp;Christian Corda","doi":"10.1002/prop.202300195","DOIUrl":"10.1002/prop.202300195","url":null,"abstract":"&lt;p&gt;In this paper, in the classical framework, the lower bounds for the sensitivities of the generalized Lemaitre Tolman Bondi metric are evaluated. The calculated lower bounds via the linear dynamical systems &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;L&lt;/mi&gt;\u0000 &lt;mfrac&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mi&gt;θ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfrac&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$L_{frac{partial }{partial theta }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;L&lt;/mi&gt;\u0000 &lt;mfrac&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfrac&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$L_{frac{partial }{partial r}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;L&lt;/mi&gt;\u0000 &lt;mfrac&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;∂&lt;/mi&gt;\u0000 &lt;mi&gt;ϕ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfrac&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$L_{frac{partial }{partial phi }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; are &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mi&gt;ln&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mi&gt;ln&lt;/mi&gt;\u0000 &lt;mo&gt;|&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;′&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;|&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mi&gt;ln&lt;/mi&gt;\u0000 &lt;mo&gt;|&lt;/mo&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mo&gt;|&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$-ln 2+ln|{(dot{R}B)}^{2}-{(R^{prime })}^{2}|-2ln|B|$&lt;/annotation&gt;\u0000 ","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139922760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Collapsing Shear-Free Anisotropic Embedding Star Model in \u0000 \u0000 \u0000 f\u0000 (\u0000 R\u0000 )\u0000 \u0000 $f(R)$\u0000 Gravity","authors":"Hammad Nazar,&nbsp;Ghulam Abbas,&nbsp;Athar Abbas,&nbsp;Shahid Qaisar","doi":"10.1002/prop.202300250","DOIUrl":"10.1002/prop.202300250","url":null,"abstract":"<p>The current paper studied the dynamics of shear-free and spherically symmetric collapsing stars by incorporating the features of anisotropic dissipative fluid in the realm of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>R</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(R)$</annotation>\u0000 </semantics></math> gravity. A complete radiative star model that describes the early static configuration obeying the embedding class 1 approach is generated. To acquittance the exact solutions of the geometric variables, a specific form of pressure anisotropy along with a time-dependent Karmarkar condition is employed, leading to a spacetime solution that seems to be potentially reliable and regular throughout the collapse process. The matching conditions have been thoroughly investigated between the interior geometry and the Vaidya outgoing solution over the junction interface. The physical attributes of our solutions to the Einstein field equations under two viable and cosmologically well-consistent models of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>R</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(R)$</annotation>\u0000 </semantics></math> are manifested. The presented features are in a stable equilibrium state and sustainable to model a dynamic structure of gravitational collapse without forming the black hole.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"72 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139922873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}