Eur. Phys. J. C (2012) 72: 1866
https://doi.org/10.1140/epjc/s10052-012-1866-8

Regular Article - Theoretical Physics

Generalized self-similar scalar-tensor theories

Dept. Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040, Madrid, Spain

^* e-mail: abelcal@ciccp.es

Received: 13 November 2011
Revised: 26 December 2011
Published online: 31 January 2012

Abstract

In order to analyze how the gravitational constant, G, and the cosmological constant, Λ, may vary we study through symmetry principles the form of the functions in the generalized scalar-tensor theories under the self-similar hypothesis. The results obtained are absolutely general and valid for all the Bianchi models and the flat FRW one. We study the concrete example of the Kantowski–Sachs model finding some new exact self-similar solutions.