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Brane-world cosmology and varying G
(World Scientific, 2010-07)
We consider a brane-world cosmological model coupled to a bulk scalar field. Since the brane tension turns out to be proportional to Newton’s coupling G, in such a model a time variation of G naturally occurs. By resorting ...
Observational constraints on holographic tachyonic dark energy in interaction with dark matter
(IOP PUBLISHING LTD, 2010)
We discuss an interacting tachyonic dark energy model in the context of the holographic principle. The potential of the holographic tachyon field in interaction with dark matter is constructed. The model results are compared ...
Reheating in holographic cosmology and connecting to Λ-MSSM constructions for particle physics
(2021-09-01)
In this paper we model the transition from the non-geometric holographic cosmology regime, to the usual radiation dominated (RD) cosmology, known as reheating in the case of (perturbative) inflation. We find that we can ...
Solution of the cosmological constant problem within holographic cosmology
(2020-02-10)
Within the holographic cosmology paradigm, specifically the model of McFadden and Skenderis, but more generally than that, the cosmological constant is found to naturally flow from a large value, to a small value, which ...
Testing extended Jordan-Brans-Dicke theories with future cosmological observations
(Institute of Physics Publishing, 2019)
© 2019 IOP Publishing Ltd and Sissa Medialab.The extended Jordan-Brans-Dicke (eJBD) theory of gravity is constrained by a host of astrophysical and cosmological observations spanning a wide range of scales. The current ...
Cosmological term and fundamental physics
(World Scientific Publ Co Pte Ltd, 2014)
A natural cosmological constant from chameleons
(2015-07-01)
We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru-Kallosh-Linde-Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the ...
Time variation of fundamental constants in nonstandard cosmological models
(American Physical Society, 2017-10)
In this work we have studied the lithium problem in nonstandard cosmological models. In particular, by using the public code alterbbn, we have included in the computation of the primordial light nuclei abundances, the ...
Gravidade unimodular como um possível cenário cosmológico
(Universidade Federal de São Paulo, 2022-11-05)
O presente estudo, que constitui um trabalho de conclusão de curso de especialização em Teoria da Relatividade, tem como objetivo solucionar o problema da constante cosmológica com uso da teoria alternativa à Relatividade ...