International Journal of Modern Physics D最新文献

{"title":"Primordial cosmology of an emergent-like universe from modified gravity: Reconstruction and phenomenology optimization with a genetic algorithm","authors":"V. K. Oikonomou, Gregory Kafanelis","doi":"10.1142/s0218271823501146","DOIUrl":"https://doi.org/10.1142/s0218271823501146","url":null,"abstract":"<p>General relativity has been the dominant paradigm theory of gravity for the last century, it manages to explain a plethora of astronomical and cosmological observations with high accuracy. A major challenge faced by general relativity is, that it predicts a singularity as the beginning of our universe. In this paper, we shall explore a well-known idea in the literature that of the emergent universe and its viability according to Planck 2018 data and BBN constraints.</p>","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125640","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":"Equilibrium of charged fluid around a Kerr black hole immersed in a magnetic field: Variation of angular momentum","authors":"Audrey Trova","doi":"10.1142/s0218271823501122","DOIUrl":"https://doi.org/10.1142/s0218271823501122","url":null,"abstract":"<p>This work presents analytically constructed equilibrium structures of charged perfect fluids orbiting Kerr Black holes embedded in an asymptotically uniform magnetic field. Our focus is on the effect of the nonconstant angular momentum distribution through the disk, as well as its combined effect with the external magnetic field and the fluid charge. We demonstrate that the three parameters of our study have a significant impact on the various features of the accretion disk: the shape, the size of the disk and the characteristic of the fluid, as the pressure and the rest-mass density. Through our investigation, we observe substantial deviations from both the uncharged thick disk model and the charged disk model with constant angular momentum.</p>","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125558","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 comparative study of wormhole models in f(R,T) gravity","authors":"Chanchal Chawla, A. Dixit, A. Pradhan, S. Krishnannair","doi":"10.1142/s0218271823501079","DOIUrl":"https://doi.org/10.1142/s0218271823501079","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138998349","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":"Nonlinear electrodynamical lensing of electromagnetic waves on the dipole magnetic field of the magnetar","authors":"Beisen Nurzada, M. Abishev, S. Toktarbay, T. Yernazarov, Yerlan Aimuratov, M. Khassanov","doi":"10.1142/s0218271823501067","DOIUrl":"https://doi.org/10.1142/s0218271823501067","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999505","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":"Diffeomorphism invariance and quantum mechanical paradoxes","authors":"Adam Dukehart, David Mattingly","doi":"10.1142/s0218271823501092","DOIUrl":"https://doi.org/10.1142/s0218271823501092","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138970673","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":"Entanglement and Quantum teleportation in terms of Dirac modes observed by accelerated observers","authors":"Yue Dai, Yu Shi","doi":"10.1142/s0218271823501043","DOIUrl":"https://doi.org/10.1142/s0218271823501043","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138996319","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":"Thermal fluctuations of (non)linearly charged BTZ black hole in massive gravity","authors":"B. Pourhassan, S. H. Hendi, S. Upadhyay, I. Sakalli, E. Saridakis","doi":"10.1142/s0218271823501109","DOIUrl":"https://doi.org/10.1142/s0218271823501109","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138996369","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":"Analogy of space time as un elastic medium - Can we establish a thermal expansion coefficient of space from the cosmological constant Λ ?-","authors":"Izabel David","doi":"10.1142/s0218271823500918","DOIUrl":"https://doi.org/10.1142/s0218271823500918","url":null,"abstract":"This paper advances the state-of-the-art by extending the study of the analogy between the fabric of spacetime and elasticity. As no prior work exists about a potential spacetime thermal expansion coefficient [Formula: see text], we explore the analogy of general relativity with the theory of elasticity by considering the cosmological constant [Formula: see text] as an additional space curvature of the structure of space due to a thermal gradient coming from the cosmic web and the cold vacuum and we propose [Formula: see text] with [Formula: see text] being the curvature radius of the space fabric. It follows from this analogy and from the supposed space model consisting of thin sheets of Planck thickness [Formula: see text] curved by this thermal gradient [Formula: see text]T a possible thermal expansion coefficient of the equivalent elastic medium modeling the space [Formula: see text] of the order of [Formula: see text][Formula: see text]K[Formula: see text]. As spacetime and not only space must be considered in general relativity, this paper also proposes an innovative approach which consists in introducing into the interval ds 2 of special relativity a temperature effect [Formula: see text] (entropy variations correlated with time laps, based on temperature variations affecting always physically the clocks) based on different thermal expansion coefficients for space and time with for the flow of time [Formula: see text]. With [Formula: see text] 10 6 [Formula: see text]K, [Formula: see text], the associate time interval is [Formula: see text][Formula: see text]s and [Formula: see text]. The consequence of this hypothesis is that dark energy potentially becomes a thermal spacetime curvature [Formula: see text] with [Formula: see text] equal to [Formula: see text] or [Formula: see text] depending of the temperature, the thermal entropy variation of the universe, the Planck thickness and time, that increases since the Big bang, depending on thermal expansion coefficients for spacetime [Formula: see text] and [Formula: see text] as a function, respectively, of [Formula: see text], [Formula: see text], in opposition to spacetime curvature gravity due to mass/energy density as described in general relativity.","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135191122","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":"Colliding fields in two-dimensional dilaton gravity background","authors":"Mustafa Halilsoy, Chia-Li Hsieh","doi":"10.1142/s0218271823500955","DOIUrl":"https://doi.org/10.1142/s0218271823500955","url":null,"abstract":"The ([Formula: see text])-dimensional dilatonic background geometry of [C. Callan, S. Giddings, J. Harvey and A. Strominger, Phys. Rev. D 45 (1992) R1005] admits an infinite class of colliding wave solutions. We give examples from real and ghost fields with bounded/unbounded profiles. In particular, colliding ghost fields in the “lineland” geometry create particle-like wormholes. Such wormholes, however, collapse to a black hole whenever the supporting ghosts turn off. Lastly, it is shown that the vacuum collision of null fields yields a ghost wormhole which is unstable.","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135293269","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":"2024 Awards for Essays On Gravitation","authors":"","doi":"10.1142/s0218271823820011","DOIUrl":"https://doi.org/10.1142/s0218271823820011","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135430788","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}