Zobrazeno 1 - 10
of 106
pro vyhledávání: '"Kayoomars Karami"'
Autor:
Milad Solbi, Kayoomars Karami
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 84, Iss 9, Pp 1-20 (2024)
Abstract Here, we investigate the formation of primordial black holes (PBHs) in non-minimal coupling Gauss–Bonnet inflationary model in the presence of power-law potentials. We employ a two part coupling function to enhance primordial curvatures at
Externí odkaz:
https://doaj.org/article/185bcc66942b4c73bad23146d0fb37a7
Autor:
Soma Heydari, Kayoomars Karami
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 84, Iss 2, Pp 1-12 (2024)
Abstract Here, generation of PBHs and secondary GWs from non-canonical inflation with quartic potential have been probed. It is illustrated that, quartic potential in non-canonical setup with a generalized power-law Lagrangian density can source a co
Externí odkaz:
https://doaj.org/article/7ebd78cadddc4bd3936447d3b73acab3
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 84, Iss 1, Pp 1-12 (2024)
Abstract Here, we study the generalized second law (GSL) of thermodynamics in the framework of massive gravity. To do this, we consider a FRW universe filled only with matter and enclosed by the apparent horizon. In addition, we consider two models i
Externí odkaz:
https://doaj.org/article/169e4b1448d644599e71b1e6d1bb1673
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 8, Pp 1-18 (2022)
Abstract We study the non-Gaussianity and secondary Gravitational Waves (GWs) in the process of the Primordial Black Holes (PBHs) production from inflation. In our work, we focus on the $$\alpha $$ α -attractor inflation model in which a tiny bump i
Externí odkaz:
https://doaj.org/article/49e30695e21b41368d8cc315516b2d4b
Autor:
Ali Ashrafzadeh, Kayoomars Karami
Publikováno v:
The Astrophysical Journal, Vol 965, Iss 1, p 11 (2024)
In this study, we investigate the formation of primordial black holes (PBHs) in a scalar field inflationary model coupled to the Gauss–Bonnet term with fractional power-law potentials. The coupling function enhances the curvature perturbations, the
Externí odkaz:
https://doaj.org/article/818df5ab0a8e49829ccca36a43e8a435
Autor:
Soma Heydari, Kayoomars Karami
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 1, Pp 1-16 (2022)
Abstract We investigate the generation of primordial black holes (PBHs) with the aid of gravitationally increased friction mechanism originated from the nonminimal field derivative coupling (NMDC) to gravity framework, with the quartic potential. App
Externí odkaz:
https://doaj.org/article/e2e158d533cc4ac69ab1cb425ae76245
Autor:
Milad Solbi, Kayoomars Karami
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 10, Pp 1-12 (2021)
Abstract Within the framework of inflationary model with field-dependent kinetic term for quartic and natural potentials, we investigate generation of the primordial black holes (PBHs) and induced gravitational waves (GWs). In this setup, we consider
Externí odkaz:
https://doaj.org/article/354b0edf1ea1421f89ca4f7ab9f7b8e3
Publikováno v:
The Astrophysical Journal, Vol 944, Iss 2, p 194 (2023)
Observations show that there are twisted magnetic flux tubes and plasma flow throughout the solar atmosphere. The main purpose of this work is to obtain the damping rate of sausage modes in the presence of magnetic twist and plasma flow. We obtain th
Externí odkaz:
https://doaj.org/article/aa251ae29b83464cb2b14e0133aa8812
Autor:
Zeinab Teimoori, Kayoomars Karami
Publikováno v:
Nuclear Physics B, Vol 921, Iss C, Pp 25-38 (2017)
We study inflation within the framework of non-canonical scalar field. In this scenario, we obtain the inflationary observables such as the scalar spectral index, the tensor-to-scalar ratio, the running of the scalar spectral index as well as the equ
Externí odkaz:
https://doaj.org/article/149aa47b21184bb694d9826f6e38a0b6
Autor:
Behzad Tahmasebzadeh, Kayoomars Karami
Publikováno v:
Nuclear Physics B, Vol 918, Iss C, Pp 1-10 (2017)
Within the framework of Brans–Dicke gravity, we investigate inflation with the quartic potential, λφ4/4, in the presence of generalized Brans–Dicke parameter ωGBD(φ). We obtain the inflationary observables containing the scalar spectral index
Externí odkaz:
https://doaj.org/article/d0e96d89cf0f45ff944d84bd4617931d