Zobrazeno 1 - 10
of 101
pro vyhledávání: '"Gregoris, Daniele"'
Publikováno v:
PLB, 842, 137962, 2023
We address the question of the uniqueness of spatially flat $\Lambda$CDM-like evolution for FLRW cosmologies in General Relativity, i.e. whether any model other than the spatially flat $\Lambda$CDM can give rise to the same type of scale factor evolu
Externí odkaz:
http://arxiv.org/abs/2208.04596
Autor:
Gregoris, Daniele, Ong, Yen Chin
Publikováno v:
Annals of Physics 452 (2023) 169287
The Chandrasekhar limit for white dwarfs has been confirmed by many astrophysical observations. However, how to obtain it theoretically in models which rely on other-than-Heisenberg's uncertainty principles, which are predicted by some quantum gravit
Externí odkaz:
http://arxiv.org/abs/2202.13904
Autor:
Gregoris, Daniele, Ong, Yen Chin
Publikováno v:
Phys. Rev. D 105, 104017 (2022)
Partly motivated by the arrow of time problem in cosmology and the Weyl curvature hypothesis formulated by Roger Penrose, previous works in the literature have proposed - among other possibilities - the square of the Weyl curvature, as being the unde
Externí odkaz:
http://arxiv.org/abs/2109.11968
Autor:
Gregoris, Daniele1 (AUTHOR) danielegregoris@libero.it
Publikováno v:
European Physical Journal C -- Particles & Fields. Apr2024, Vol. 84 Issue 4, p1-18. 18p.
Publikováno v:
Eur. Phys. J. C (2021) 81:684
Different theories of gravity can admit the same black hole solution, but the parameters usually have different physical interpretations. In this work we study in depth the linear term $\beta r$ in the redshift function of black holes, which arises i
Externí odkaz:
http://arxiv.org/abs/2106.05205
Autor:
Chakraborty, Saikat, Gregoris, Daniele
Publikováno v:
EPJC (2021) 81:944
Some cosmological models based on the gravitational theory $f(R) = R+\zeta R^2$, and on fluids obeying to the equations of state of Redlich-Kwong, Berthelot, and Dieterici are proposed for describing smooth transitions between different cosmic epochs
Externí odkaz:
http://arxiv.org/abs/2103.07718
Publikováno v:
International Journal of Modern Physics A (2022)
In this paper, we will deepen the understanding of some fluid models proposed by other authors for the description of dark energy. Specifically, we will show that the so-called (Modified) Berthelot fluid is the hydrodynamic realization of the free Di
Externí odkaz:
http://arxiv.org/abs/2010.05278
Autor:
Gregoris, Daniele, Rosquist, Kjell
Publikováno v:
The European Physical Journal Plus 136:45 (2021)
Applying the Sachs formalism, the optical properties encoded in the distance modulus are studied along curves exhibiting local rotational symmetry for some closed inhomogeneous cosmological models whose mass content is discretized by Schwarzschild-li
Externí odkaz:
http://arxiv.org/abs/2006.00855
Publikováno v:
EPJC (2021) 81:544
In this paper, after reconstructing the redshift evolution of the Hubble function by adopting Gaussian process techniques, we estimate the best-fit parameters for some flat Friedmann cosmological models based on a Modified Chaplygin Gas interacting w
Externí odkaz:
http://arxiv.org/abs/2005.01891
Publikováno v:
Phys. Rev. D 102, 023539 (2020)
Our Universe has an arrow of time. In accordance with the second law of thermodynamics, entropy has been increasing ever since the Big Bang. The fact that matter is in thermal equilibrium in the very early Universe, as indicated by the cosmic microwa
Externí odkaz:
http://arxiv.org/abs/2004.10222