Zobrazeno 1 - 10
of 75
pro vyhledávání: '"Fakhry, Saeed"'
In this study, we investigate gravitational lensing within modified gravity frameworks, focusing on the Hu-Sawicki $f(R)$ and normal branch Dvali-Gabadadze-Porrati (nDGP) models, and we compare these results with those obtained from general relativit
Externí odkaz:
http://arxiv.org/abs/2411.06945
Publikováno v:
The Astrophysical Journal (2024)
In this study, we investigate the impact of modified gravity on the merger rate of compact binaries within dark-matter spikes surrounding super-massive black holes (SMBHs). Specifically, we calculate binary merger rates involving primordial black hol
Externí odkaz:
http://arxiv.org/abs/2408.11995
Publikováno v:
Physics of the Dark Universe (2024)
In this study, we explore gravitational lensing using more realistic dark matter halo models, moving beyond the limitations of spherical-collapse approximations. Through analytical calculations employing various mass functions, we address critical fa
Externí odkaz:
http://arxiv.org/abs/2405.20256
Publikováno v:
The Astrophysical Journal (2024)
In this work we investigate the merger rate of primordial black hole-neutron star (PBH-NS) binaries in two widely-studied modified gravity (MG) models: Hu-Sawicki $f(R)$ gravity and the normal branch of Dvali-Gabadadze-Porrati (nDGP) gravity. In our
Externí odkaz:
http://arxiv.org/abs/2401.15171
Publikováno v:
Physics of the Dark Universe (2024)
Ultradense dark matter halos (UDMHs) are high concentrations of dark matter, assumed to have formed deep in the radiation-dominated era from amplified primordial perturbations. In this work we improve the previous works for the calculation of UDMH ab
Externí odkaz:
http://arxiv.org/abs/2311.15307
Autor:
Fakhry, Saeed
Publikováno v:
The Astrophysical Journal (2024)
Primordial black holes (PBHs) are known as one of the potential candidates for dark matter. They are expected to have formed due to the direct gravitational collapse of density fluctuations in the early Universe. Therefore, the study of the merger ra
Externí odkaz:
http://arxiv.org/abs/2308.11049
Autor:
Del Popolo, Antonino, Fakhry, Saeed
Publikováno v:
Physics of the Dark Universe (2023)
In this work, we extend the model proposed by White concerning the post-collapse evolution of density peaks while considering the role of angular momentum. On a timescale smaller than the peak collapse, $t_{0}$, the inner regions of the peak reach th
Externí odkaz:
http://arxiv.org/abs/2305.19817
Autor:
Fakhry, Saeed, Salehnia, Zahra, Shirmohammadi, Azin, Yengejeh, Mina Ghodsi, Firouzjaee, Javad T.
Publikováno v:
The Astrophysical Journal (2023)
Nowadays, the existence of supermassive black holes (SMBHs) in the center of galactic halos is almost confirmed. An extremely dense region referred to as dark-matter spike is expected to form around central SMBHs as they grow and evolve adiabatically
Externí odkaz:
http://arxiv.org/abs/2301.02349
Autor:
Fakhry, Saeed, Del Popolo, Antonino
Publikováno v:
Phys. Rev. D (2023)
In this work, we study the effect of a high-precision semianalytical mass function on the merger rate of primordial black holes (PBHs) in dark matter halos. For this purpose, we first explain a theoretical framework for dark matter halo models and in
Externí odkaz:
http://arxiv.org/abs/2212.08646
Publikováno v:
Physics of the Dark Universe (2023)
Cosmic voids are known as underdense substructures of the cosmic web that cover a large volume of the Universe. It is known that cosmic voids contain a small number of dark matter halos, so the existence of primordial black holes (PBHs) in these secl
Externí odkaz:
http://arxiv.org/abs/2210.13558