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Kourosh Nozari

Kourosh Nozari

Academic rank: Professor
ORCID: https://orcid.org/0000-0003-4368-5823
Education: PhD.
ScopusId: 9276301800
HIndex:
Faculty: Science
Address: Department of Theoretical Physics, Faculty of Basic Sciences, University of Mazandaran, P. O. Box 47416-95447, Babolsar, Iran
Phone: 01135302482

Research

Title
On the cosmological viability of the Hu–Sawicki type modified induced gravity
Type
JournalPaper
Keywords
Braneworld cosmology Phantom mimicry Dynamical system Cosmography
Year
2011
Journal Physics Letters B
DOI
Researchers Kourosh Nozari ، Faezeh Kiani

Abstract

It has been shown recently that the normal branch of a DGP braneworld scenario self-accelerates if the induced gravity on the brane is modified in the spirit of f (R) modified gravity. Within this viewpoint, we investigate cosmological viability of the Hu–Sawicki type modified induced gravity. Firstly, we present a dynamical system analysis of a general f (R)-DGP model. We show that in the phase space of the model, there exist three standard critical points; one of which is a de Sitter point corresponding to accelerating phase of the universe expansion. The stability of this point depends on the effective equation of state parameter of the curvature fluid. If we consider the curvature fluid to be a canonical scalar field in the equivalent scalar-tensor theory, the mentioned de Sitter phase is unstable, otherwise it is an attractor, stable phase. We show that the effective equation of state parameter of the model realizes an effective phantom-like behavior. A cosmographic analysis shows that this model, which admits a stable de Sitter phase in its expansion history, is a cosmologically viable scenario.