Zobrazeno 1 - 10
of 229
pro vyhledávání: '"V. K. Oikonomou"'
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 6, Pp 1-15 (2021)
Abstract In this paper we shall consider spherically symmetric spacetime solutions describing the interior of stellar compact objects, in the context of higher-order curvature theory of the $${{\mathrm {f(R)}}}$$ f ( R ) type. We shall derive the non
Externí odkaz:
https://doaj.org/article/65cc63ed72a44e14ac9a11822f10987f
Publikováno v:
Universe, Vol 8, Iss 9, p 484 (2022)
In this short review, we discuss how Earth’s climatological and geological history and also how the shadows of galactic black holes might reveal our Universe’s past evolution. Specifically we point out that a pressure singularity that occurred in
Externí odkaz:
https://doaj.org/article/9649679360364005b79d35adeb73f316
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 79, Iss 7, Pp 1-24 (2019)
Abstract In this work we investigate the inflationary phenomenological implications of a recently developed ghost-free Gauss–Bonnet theory of gravity. The resulting theory can be viewed as a scalar Einstein–Gauss–Bonnet theory of gravity, so by
Externí odkaz:
https://doaj.org/article/20cafdb309a74cc2b64fe895e0396350
Publikováno v:
Symmetry, Vol 10, Iss 10, p 463 (2018)
We study the cosmic evolution of non-minimally coupled f ( R , T ) gravity in the presence of matter fluids consisting of collisional self-interacting dark matter and radiation. We study the cosmic evolution in the presence of collisional matter, and
Externí odkaz:
https://doaj.org/article/15f811d0521743d4a98e3bdf3d856106
Autor:
V. K. Oikonomou
Publikováno v:
Universe, Vol 2, Iss 2, p 10 (2016)
In this paper, we study under which conditions the Reissner–Nordström anti-de Sitter black hole can be a solution of the vacuum mimetic F ( R ) gravity with Lagrange multiplier and mimetic scalar potential. As the author demonstrates, the resultin
Externí odkaz:
https://doaj.org/article/2a179abde99748e8918994aaaa005708
In this paper, we worked in the framework of an inflationary $f(R,T)$ theory, in the presence of a canonical scalar field. More specifically, the $f(R,T)=\gamma R+2\kappa\alpha T$ gravity. The values of the dimensionless parameters $\alpha$ and $\gam
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b0434b36b1c86496e7eb2c472f2783f3
http://arxiv.org/abs/2303.14724
http://arxiv.org/abs/2303.14724
In this article we present an alternative formalism for the inflationary phenomenology of rescaled Einstein-Gauss-Bonnet models which are in agreement with the GW170817 event. By constraining the propagation velocity of primordial tensor perturbation
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fa9536e9f243562d261dbf869f4b01b6
http://arxiv.org/abs/2303.14594
http://arxiv.org/abs/2303.14594
Autor:
V. K. Oikonomou
Publikováno v:
Physical Review
We investigate the effects of short axion kination eras on the energy spectrum of the primordial gravitational waves corresponding to modes that re-enter the Hubble horizon at the post-electroweak symmetry breaking epoch, well within the radiation do
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::600f5cb0f3db3a811c7bb1ea3d987bfa
http://arxiv.org/abs/2303.05889
http://arxiv.org/abs/2303.05889
Autor:
V K Oikonomou
This study focuses on the static neutron star perspective for two types of cosmological inflationary attractor theories, namely the induced inflationary attractors and the quadratic inflationary attractors. The two cosmological models can be discrimi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0cfe899581908d7b43c30e59782d3a8b
Autor:
S. D. Odintsov, V. K. Oikonomou
In this work we study static neutron stars in the context of several inflationary models which are popular in cosmology. These inflationary models are non-minimally coupled scalar theories which yield a viable inflationary phenomenology in both Jorda
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::485d1e868ddd03251650aa9a008aa3eb