Zobrazeno 1 - 10
of 225
pro vyhledávání: '"A Heydarzade"'
Cotton theory (CT) introduces a higher derivative extension of General Relativity (GR) characterized by third-rank field equations. Recently, key distinctions between CT and GR concerning wave and vacuum solutions have been highlighted in [1, 2]. In
Externí odkaz:
http://arxiv.org/abs/2412.06953
We study wave metrics in the context of Cotton Gravity and Conformal Killing Gravity. First, we consider pp-wave metrics with flat and non-flat wave surfaces and show that they are exact solutions to the field equations of these theories. More explic
Externí odkaz:
http://arxiv.org/abs/2409.06257
Publikováno v:
Phys. Rev. D 110, 024073 (2024)
Recently we showed that in FLRW cosmology, the contribution from higher curvature terms in any generic metric gravity theory to the energy-momentum tensor is of the perfect fluid form. Such a geometric perfect fluid can be interpreted as a fluid rema
Externí odkaz:
http://arxiv.org/abs/2401.09784
Publikováno v:
Eur. Phys. J. C 84, 582 (2024)
To understand the nature of a black hole shadow in dynamical spacetimes, we construct an analytical model of a dynamical photon sphere in the context of the Bonnor-Vaidya spacetime. Comparing the resulting photon sphere radius with the one in Vaidya
Externí odkaz:
http://arxiv.org/abs/2311.08930
Publikováno v:
Phys. Rev. D 108, 044073 (2023)
In the realm of astrophysics, black holes exist within nonvacuum cosmological backgrounds, making it crucial to investigate how these backgrounds influence the properties of black holes. In this work, we first introduce a novel static spherically-sym
Externí odkaz:
http://arxiv.org/abs/2307.04556
Autor:
Heydarzade, Yaghoub, Ranjbar, Maryam
Publikováno v:
Eur. Phys. J. Plus 138, 703 (2023)
Wormhole configurations in Einstein's general theory of relativity (GR) require exotic matter sources violating the weak energy condition (WEC). Rastall's theory is a generalization of GR in its matter source considering a nonconserved energy-momentu
Externí odkaz:
http://arxiv.org/abs/2307.04259
Publikováno v:
Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Qum, Vol 6, Iss 2, Pp 82-87 (2012)
Background and Objectives: Obesity due to inactivity and sedentary as an epidemic phenomenon is growing up. The purpose of this study is to determine correlation between obesity and thinness with blood CRP and fibrinogen in young girl students. Me
Externí odkaz:
https://doaj.org/article/9ee0f043f2e34a49a3c896dae7f68cd1
Publikováno v:
Лесной журнал, Iss 3, Pp 130-139 (2024)
Atmospheric pollution by anthropogenic emissions leads to an increase in the content of aerosols in the air. This causes distortions in the Earth remote sensing data in the visible ranges. Thus, the use of vegetation indices, in particular, the norma
Externí odkaz:
https://doaj.org/article/a2fd9163c902478784d0500dd75ba9bd
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 84, Iss 6, Pp 1-11 (2024)
Abstract To understand the nature of a black hole shadow in dynamical spacetimes, we construct an analytical model of a dynamical photon sphere in the context of the Bonnor–Vaidya spacetime. Comparing the resulting photon sphere radius with the one
Externí odkaz:
https://doaj.org/article/b5fcbe9c396243bfbe6d53286da3fc26
Publikováno v:
Phys. Rev. D 105, 044004 (2022)
We study Kerr-Schild-Kundt class of metrics in generic gravity theories with Maxwell's field. We prove that these metrics linearize and simplify the field equations of generic gravity theories with Maxwell's field.
Comment: 15 pages, no figures,
Comment: 15 pages, no figures,
Externí odkaz:
http://arxiv.org/abs/2112.07736