Eur. Phys. J. C (2016) 76: 17
https://doi.org/10.1140/epjc/s10052-015-3872-0

Regular Article - Theoretical Physics

Mass-varying massive gravity with k-essence

¹ Department of Physics, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
² The Institute for Fundamental Study, Naresuan University, Phitsanulok, 65000, Thailand
³ Thailand Center of Excellence in Physics, Ministry of Education, Bangkok, 10400, Thailand

^* e-mail: l_tannukij@hotmail.com

Received: 14 November 2015
Accepted: 22 December 2015
Published online: 14 January 2016

Abstract

For a large class of mass-varying massive-gravity models, the graviton mass cannot provide the late-time cosmic expansion of the universe due to its vanishing at late time. In this work, we propose a new class of mass-varying massive gravity models, in which the graviton mass varies according to a kinetic term of a k-essence field. By using a more general form of the fiducial metric, we found a solution such that a non-vanishing graviton mass can drive the accelerated expansion of the universe at late time. We also perform dynamical analyses of such a model and find that without introducing the k-essence Lagrangian, the graviton mass can be responsible for both dark contents of the universe, namely dark energy, which drives the accelerated expansion of the universe, and non-relativistic matter, which plays the role of dark matter. Moreover, by including the k-essence Lagrangian, we find that it is possible to alleviate the so-called cosmic coincidence problem.