Cosmology or Catastrophe? A non-minimally coupled scalar in an inhomogeneous universe

Autor:	Caputa, Pawel, Haque, Sheikh Shajidul, Olson, Joseph, Underwood, Bret
Rok vydání:	2013
Předmět:	High Energy Physics - Theory Astrophysics - Cosmology and Extragalactic Astrophysics
Zdroj:	Class. Quantum Grav. 30 (2013) 195013
Druh dokumentu:	Working Paper
DOI:	10.1088/0264-9381/30/19/195013
Popis:	A non-minimally coupled scalar field can have, in principle, a negative effective Planck mass squared which depends on the scalar field. Surprisingly, an isotropic and homogeneous cosmological universe with a non-minimally coupled scalar field is perfectly smooth as the rolling scalar field causes the effective Planck mass to change sign and pass through zero. However, we show that any small deviations from homogeneity diverge as the effective Planck mass vanishes, with catastrophic consequences for the cosmology. The physical origin of the divergence is due to the presence of non-zero scalar anisotropic stress from the non-minimally coupled scalar field. Thus, while the homogeneous and isotropic cosmology appears surprisingly sensible when the effective Planck mass vanishes, inhomogeneities tell a different story. Comment: 10 pages, 2 figures. v2: Updated references. v3: Added figure, minor clarifications in Appendix. Matches published version
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1306.0012 Zobrazit plný text záznamu View this record from Arxiv