New Holographic Dark Energy in Chern-Simons Gravity and Cosmography

Abstract

We have considered a five-dimensional action, which is composed of a gravitational sector and a sector of matter, where the gravitational sector is given by a Chern-Simons gravity action instead of the Einstein-Hilbert action and where the matter sector is given by the so-called perfect fluid with barotropic EoS and new holographic dark energy. We will study the dynamic formulation of Chern-Simons gravity, where the coupling constant is promoted to a scalar field with potential. We have studied the implications of replacing the Einstein-Hilbert action by the Chern-Simons action on the cosmological evolution for a 5D FRW metric. The deceleration parameter shows that our considered model cannot cross the phantom divide. Also the natures of the cosmography parameters are examined in Chern-Simons gravity.