English

Cosmology with nonminimal kinetic coupling and a Higgs-like potential

General Relativity and Quantum Cosmology 2017-09-18 v2 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as κGμνϕ,μϕ,ν\kappa G^{\mu\nu}\phi_{,\mu}\phi_{,\nu}, and the Higgs-like potential V(ϕ)=λ4(ϕ2ϕ02)2V(\phi)=\frac{\lambda}{4}(\phi^2-\phi_0^2)^2. Using the dynamical system method, we analyze stationary points, their stability, and all possible asymptotical regimes of the model under consideration. We show that the Higgs field with the kinetic coupling provides an existence of accelerated regimes of the Universe evolution. There are three possible cosmological scenarios with acceleration: (i) {\em The late-time inflation} when the Hubble parameter tends to the constant value, H(t)H=(23πGλϕ04)1/2H(t)\to H_\infty=(\frac23 \pi G\lambda\phi_0^4)^{1/2} as tt\to\infty, while the scalar field tends to zero, ϕ(t)0\phi(t)\to 0, so that the Higgs potential reaches its local maximum V(0)=14λϕ04V(0)=\frac14 \lambda\phi_0^4. (ii) {\em The Big Rip} when H(t)(tt)1H(t)\sim(t_*-t)^{-1}\to\infty and ϕ(t)(tt)2\phi(t)\sim(t_*-t)^{-2}\to\infty as ttt\to t_*. (iii) {\em The Little Rip} when H(t)t1/2H(t)\sim t^{1/2}\to\infty and ϕ(t)t1/4\phi(t)\sim t^{1/4}\to\infty as tt\to\infty. Also, we derive modified slow-roll conditions for the Higgs field and demonstrate that they lead to the Little Rip scenario.

Keywords

Cite

@article{arxiv.1510.03264,
  title  = {Cosmology with nonminimal kinetic coupling and a Higgs-like potential},
  author = {Jiro Matsumoto and Sergey V. Sushkov},
  journal= {arXiv preprint arXiv:1510.03264},
  year   = {2017}
}

Comments

29 pages, 11 figures, discussions and references added, to be published on JCAP