Bianchi VI₀ in Scalar and Scalar-Tensor Cosmologies

الأصل · EN

We study several cosmological models with Bianchi VI₀ symmetries under the self-similar approach. In order to study how the constantsG and Λ may vary, we propose three scenarios where such constants are considered as time functions. The first model is a perfect fluid. We find that the behavior of G and Λ are related. If G behaves as a growing time function then Λ is a positive decreasing time function but if G is decreasing then Λ is negative. For this model we have found a new solution. The second model is a scalar field, where in a phenomenological way, we consider a modification of the Klein-Gordon equation in order to take into account the variation of G. Our third scenario is a scalar-tensor model. We find three solutions for this models where G is growing, constant or decreasing and Λ is a positive decreasing function or vanishes. We put special emphasis on calculating the curvature invariants in order to see if the solutions isotropize.