Accelerated expansion of the Universe in the presence of dark matter pressure

Abstract

Expansion dynamics of the Universe is one of the important subjects in modern cosmology. The dark energy equation of state determines this dynamics so that the Universe is in an accelerating phase. However, the dark matter can also affect the accelerated expansion of the Universe through its equation of state. In the present work, we explore the expansion dynamics of the Universe in the presence of dark matter pressure. In this regard, applying the dark matter equation of state from the observational data related to the rotational curves of galaxies, we calculate the evolution of dark matter density. Moreover, the Hubble parameter, history of scale factor, luminosity distance, and deceleration parameter are studied while the dark matter pressure is taken into account. Our results verify that the dark matter pressure leads to the higher values of the Hubble parameter at each redshift and the expansion of the Universe grows due to the DM

A study of cylindrically symmetric solutions in $$f(R, \phi , X)$$ theory of gravity

“…From that stage of matter, it is expanding at an accelerating rate [1][2][3]. The reason defined beyond this accelerating expansion is some kind of matter and energy known as Dark Matter (DM) and Dark Energy (DE) [4][5][6][7][8][9][10][11]. In 1905, Albert Einstein provided a very different approach to explain this phenomenon which is named as "Special Theory of Relativity" (STR).…”