Anisotropic k-essence cosmologies

• Autores: Chimento, Luis Pascual; Forte, Mónica
• Año de publicación: 2006
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: k-essence; Bianchi
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We investigate a Bianchi type-I cosmology with k-essence and find the set of models which dissipate the initial anisotropy. There are cosmological models with extended tachyon fields and k-essence having a constant barotropic index. We obtain the conditions leading to a regular bounce of the average geometry and the residual anisotropy on the bounce. For constant potential, we develop purely kinetic k-essence models which are dust dominated in their early stages, dissipate the initial anisotropy, and end in a stable de Sitter accelerated expansion scenario. We show that linear k-field and polynomial kinetic function models evolve asymptotically to Friedmann-Robertson-Walker cosmologies. The linear case is compatible with an asymptotic potential interpolating between Vl -γl, in the shear dominated regime, and Vl -2 at late time. In the polynomial case, the general solution contains cosmological models with an oscillatory average geometry. For linear k-essence, we find the general solution in the Bianchi type-I cosmology when the k field is driven by an inverse square potential. This model shares the same geometry as a quintessence field driven by an exponential potential. © 2006 The American Physical Society.
Fil: Chimento, Luis Pascual. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina
Fil: Forte, Mónica. Facultad de Ciencias Exactas y Naturales; Argentina