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Amir Hadi Ziaie

Amir Hadi Ziaie

Academic rank: Assistant Professor
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Education: PhD.
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Faculty: Research Institute for Astronomy and Astrophysics
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Research

Title
Effects of Rastall parameter on perturbation of dark sectors of the Universe
Type
JournalPaper
Keywords
Structure Formation, Spherical Collapse, Modified Gravity Theories
Year
2021
Journal MODERN PHYSICS LETTERS A
DOI
Researchers Amir Hadi Ziaie ، Hamid Shabani ، Shayesteh Ghaffari

Abstract

In recent years, Rastall gravity is undergoing a considerable surge in popularity. This theory purports to be a modified gravity theory with a non-conserved energy–momentum tensor (EMT) and an unusual non-minimal coupling between matter and geometry. This work looks for the evolution of homogeneous spherical perturbations within the Universe in the context of Rastall gravity. Using the spherical Top-Hat collapse model, we seek for exact solutions in linear regime for density contrast of dark matter (DM) and dark energy (DE). We find that the Rastall parameter affects crucially the dynamics of density contrasts for DM and DE and the fate of spherical collapse is different in comparison to the case of general relativity (GR). Numerical solutions for perturbation equations in nonlinear regime reveal that DE perturbations could amplify the rate of growth of DM perturbations depending on the values of Rastall parameter