Testing a dissipative kinetic k-essence model

Víctor H. Cárdenas; Norman Cruz; J. R. Villanueva

doi:10.1140/epjc/s10052-015-3366-0

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2015) 75: 148
https://doi.org/10.1140/epjc/s10052-015-3366-0

Regular Article - Theoretical Physics

Testing a dissipative kinetic k-essence model

Víctor H. Cárdenas¹^,2, Norman Cruz³ and J. R. Villanueva¹^,2^*

¹ Instituto de Física y Astronomía, Universidad de Valparaíso, Gran Bretaña 1111, Valparaiso, Chile
² Centro de Astrofísica de Valparaíso, Gran Bretaña 1111, Playa Ancha, Valparaiso, Chile
³ Departamento de Física, Universidad de Santiago de Chile, Av. Ecuador 3493, Santiago, Chile

^* e-mail: jose.villanuevalob@uv.cl

Received: 7 January 2015
Accepted: 12 March 2015
Published online: 9 April 2015

Abstract

In this work, we present a study of a purely kinetic k-essence model, characterized basically by a parameter $\alpha$ in presence of a bulk dissipative term, whose relationship between viscous pressure $\Pi$ and energy density $\rho$ of the background follows a polytropic type law, $\Pi \propto \rho ^{\lambda +1/2}$ , where $\lambda$ , in principle, is a parameter without restrictions. Analytical solutions for the energy density of the k-essence field are found in two specific cases: $\lambda =1/2$ and $\lambda =(1-\alpha )/2\alpha$ , and then we show that these solutions possess the same functional form as the non-viscous counterpart. Finally, both approaches are contrasted with observational data from type Ia supernova, and the most recent Hubble parameter measurements, and therefore, the best values for the parameters of the theory are found.