Mass-varying massive gravity with k-essence

6th IF-YITP GR+HEP+Cosmo International Symposium

Tannukij, Lunchakorn^1,2,3

Department of Physics, Faculty of Science, Mahidol University, Bangkok

10400, Thailand^1

Institute for Fundamental Study, Naresuan University, Phitsanulok

65000, Thailand^2

Department of Physics, Hanyang University, Seoul

133-891, Korea, Republic of^3

关键词: Coincidence problems;    Cosmological evolution;    Dark matter;    Dynamical analysis;    Fine tuning;    Graviton mass;    Specific class;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/883/1/012005/pdf
DOI  :  10.1088/1742-6596/883/1/012005

来源: IOP

【 摘 要 】

In this work I review the specific class of mass-varying massive gravity in which a corresponding graviton is given nonzero varying mass. Particularly in this theory, the graviton mass varies which is driven by a rolling k-essence field. Firstly, the model action is expressed along with its equations of motion. It is found from those equations of motion that not only the cosmic accelerating expansion but also the presence of dark matter can be realized in this context. Due to the complexity of its dynamics, the method of dynamical analysis is used to investigate evolutions of the cosmological system. It is found that the corresponding cosmological evolutions can explain the cosmic coincidence problem, where the effective dark matter is presented while the system is in the phase of the cosmic accelerating expansion. I then conclude that the evolutions obtained here can alleviate the cosmic coincidence problem while in some aspects the fine-tuning problem arises.