Can Chameleon Field be identified with Quintessence ?

Abstract

In the Einstein-Cartan gravitational theory with the chameleon field, changing its mass in dependence of a density of its environment, we analyze the Friedmann-Einstein equations for the Universe evolution with the expansion parameter $a$ dependent on time only. We analyze the problem of an identification of the chameleon field with quintessence, i.e. a canonical scalar field responsible for dark energy dynamics and for the acceleration of the Universe expansion. We show that since the cosmological constant, related to the relic dark energy density, is induced by torsion (Astrophys. J.829, 47 (2016)), the chameleon field may, in principle, possess some properties of quintessence such as an influence on the dark energy dynamics and the acceleration of the Universe expansion even on the late-time acceleration, but it cannot be identified with quintessence to full extent.