Cosmological aspects of cubic Galileon massive gravity

Abstract

Cubic Galileon massive gravity is a development of de Rham-Gabadadze-Tolley (dRGT) massive gravity theory in which the space of the Stueckelberg field is broken. We consider the cubic Galileon term as a scalar field coupled to the graviton field. We present a detailed study of the cosmological aspects of this theory of gravity. We analyze self-accelerating solutions of the background equations of motion to explain the accelerated expansion of the Universe. Exploiting the latest Union2 Type Ia Supernovae (SNIa) dataset, which consists of 557 SNIa, we show that cubic Galileon massive gravity theory is consistent with the observations. We also examine the tensor perturbations within the framework of this model and find an expression for the dispersion relation of gravitational waves, and show that it is consistent with the observational results.

Aether-quasi-dilaton massive gravity

“…Furthermore, due to the strong coupling problem and the nonlinear ghost instability, the scalar and vector perturbations would vanish [42]. Thus, the quasidilaton massive gravity theory has been introduced in order to solve these problems [43,44] (see also [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59]). Nevertheless, in the quasi-dilaton massive gravity there is an instability in the scalar perturbation analysis [60][61][62].…”