Pub Date : 2023-08-04DOI: 10.1142/s0218271823500803
Pretty N Khambule, R. Goswami, S. Maharaj
{"title":"Causal thermodynamics of a collapsing self similar radiation shell","authors":"Pretty N Khambule, R. Goswami, S. Maharaj","doi":"10.1142/s0218271823500803","DOIUrl":"https://doi.org/10.1142/s0218271823500803","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46452948","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}
Pub Date : 2023-08-02DOI: 10.1142/s0218271823400047
A. Zakharov
General relativity (GR) passed many astronomical tests but in majority of them GR predictions have been tested in a weak gravitational field approximation. Around 50 years ago a shadow has been introduced by J. Bardeen as a purely theoretical concept but due to an enormous progress in observational and computational facilities this theoretical prediction has been confirmed and the most solid argument for an existence of supermassive black holes in Sgr A* and M87* has been obtained.
{"title":"Shadows near supermassive black holes: from a theoretical concept to GR test","authors":"A. Zakharov","doi":"10.1142/s0218271823400047","DOIUrl":"https://doi.org/10.1142/s0218271823400047","url":null,"abstract":"General relativity (GR) passed many astronomical tests but in majority of them GR predictions have been tested in a weak gravitational field approximation. Around 50 years ago a shadow has been introduced by J. Bardeen as a purely theoretical concept but due to an enormous progress in observational and computational facilities this theoretical prediction has been confirmed and the most solid argument for an existence of supermassive black holes in Sgr A* and M87* has been obtained.","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41666151","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}
Pub Date : 2023-07-21DOI: 10.1142/s0218271823500748
A. Moreira
{"title":"Fermion localization mechanisms in f(T,𝒯 )-brane","authors":"A. Moreira","doi":"10.1142/s0218271823500748","DOIUrl":"https://doi.org/10.1142/s0218271823500748","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49361730","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}
Pub Date : 2023-07-21DOI: 10.1142/s0218271823500724
U. De, Dipankar Hazra
{"title":"Characterizations of Weakly Ricci-Symmetric Spacetimes and f(ℛ)-Gravity","authors":"U. De, Dipankar Hazra","doi":"10.1142/s0218271823500724","DOIUrl":"https://doi.org/10.1142/s0218271823500724","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45773137","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}
Pub Date : 2023-07-21DOI: 10.1142/s0218271823420166
C. Lousto, J. Healy
{"title":"In Search of the maximum lost momentum","authors":"C. Lousto, J. Healy","doi":"10.1142/s0218271823420166","DOIUrl":"https://doi.org/10.1142/s0218271823420166","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42710462","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}
Pub Date : 2023-07-13DOI: 10.1142/s0218271823500712
Pooja Vishwakarma, Parth Shah
{"title":"Stability analysis of f(Q) gravity models using Dynamical Systems","authors":"Pooja Vishwakarma, Parth Shah","doi":"10.1142/s0218271823500712","DOIUrl":"https://doi.org/10.1142/s0218271823500712","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47209407","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}
Pub Date : 2023-07-10DOI: 10.1142/s0218271823500645
Bakhtiyor Narzilloev, B. Ahmedov
The effects of a gravitomagnetic charge on the thermal radiation properties of a thin accretion disk surrounding a non-rotating black hole are studied. The studied system consists of a non-rotating black hole with a non-zero gravitomagnetic charge and a Novikov–Thorne disk that is thin and optically thick. It is found that the gravitomagnetic charge enhances the gravitational field of the central black hole, resulting in an increase in the event horizon and innermost stable circular orbit (ISCO) radii. However, the maximum flux of radiant energy from the accretion disk is reduced and shifted outward from the central object due to the effect of the gravitomagnetic charge. The thermal profile of the accretion disk also exhibits a similar dependence on the radial coordinate and the gravitomagnetic charge of the black hole. The radiative efficiency of the accretion disk decreases from around 6% to approximately 2% with an increase in the value of the gravitomagnetic charge by [Formula: see text]. The thermal spectra of the accretion disk are also shifted towards lower frequencies, corresponding to the gravitational redshift of electromagnetic radiation coming from the disk, with an increase in the value of the gravitomagnetic charge. One may conclude that the effect of the gravitomagnetic charge is opposite to the effect of black hole spin.
{"title":"Thermal radiation of thin accretion disk around Taub-NUT black hole","authors":"Bakhtiyor Narzilloev, B. Ahmedov","doi":"10.1142/s0218271823500645","DOIUrl":"https://doi.org/10.1142/s0218271823500645","url":null,"abstract":"The effects of a gravitomagnetic charge on the thermal radiation properties of a thin accretion disk surrounding a non-rotating black hole are studied. The studied system consists of a non-rotating black hole with a non-zero gravitomagnetic charge and a Novikov–Thorne disk that is thin and optically thick. It is found that the gravitomagnetic charge enhances the gravitational field of the central black hole, resulting in an increase in the event horizon and innermost stable circular orbit (ISCO) radii. However, the maximum flux of radiant energy from the accretion disk is reduced and shifted outward from the central object due to the effect of the gravitomagnetic charge. The thermal profile of the accretion disk also exhibits a similar dependence on the radial coordinate and the gravitomagnetic charge of the black hole. The radiative efficiency of the accretion disk decreases from around 6% to approximately 2% with an increase in the value of the gravitomagnetic charge by [Formula: see text]. The thermal spectra of the accretion disk are also shifted towards lower frequencies, corresponding to the gravitational redshift of electromagnetic radiation coming from the disk, with an increase in the value of the gravitomagnetic charge. One may conclude that the effect of the gravitomagnetic charge is opposite to the effect of black hole spin.","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41510986","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}
Pub Date : 2023-07-07DOI: 10.1142/s0218271823420130
A. Yahalom
{"title":"Essay written for the Gravity Research Foundation 2023 Awards for Essays on Gravitation The Virial Theorem for Retarded gravity","authors":"A. Yahalom","doi":"10.1142/s0218271823420130","DOIUrl":"https://doi.org/10.1142/s0218271823420130","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46667066","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}
Pub Date : 2023-07-07DOI: 10.1142/s0218271823420142
R. Konoplya
{"title":"The sound of the event horizon","authors":"R. Konoplya","doi":"10.1142/s0218271823420142","DOIUrl":"https://doi.org/10.1142/s0218271823420142","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47383519","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}
Pub Date : 2023-07-04DOI: 10.1142/s0218271823500700
Y. Iida
{"title":"Event horizon detection: Zenith view as seen by falling into a Schwarzschild black hole","authors":"Y. Iida","doi":"10.1142/s0218271823500700","DOIUrl":"https://doi.org/10.1142/s0218271823500700","url":null,"abstract":"","PeriodicalId":50307,"journal":{"name":"International Journal of Modern Physics D","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44632297","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}
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