New method of exponential potentials reconstruction based on given scale factor in phantonical two-field models

Abstract

We study cosmological dynamic equations of two-field phantonical models, using standard approach for constant potential in finding exact solutions. New method we proposed for reconstruction non-constant exponential potentials supporting given evolution of scale factor. The exact solutions for different types of inflation represented in explicit form. Criteria for limiting possible types of inflationary dynamics are formulated within the framework of the proposed approach. It is shown that these models explain both stages of the accelerated expansion of the universe.

Quintom fields from chiral K-essence cosmology

“…An action similar to (1) also appear in modified theories of gravity [62], and more recently in [63]. Making the variation of the action (1) with respect to the fields (g µν , φ c ) we get…”

Quintom Fields from Chiral K-Essence Cosmology

“…Note that we are working with the reduced Planck units since 8πG = 1, so this eliminates the 8πG term from the expression (1). An action similar to (1) also appears in modified theories of gravity [64], and more recently in [65]. Making the variation of the action (1) with respect to the fields (g µν , φ c ), we obtain…”

“…In order to solve the WDW equation, we propose the following solution for the wave function Ψ(ξ 1 , ξ 2 , ξ 3 ) = e p 3 ξ 3 G(ξ 1 , ξ 2 ) with p 3 = constant. Additionally, we take as an ansatz G(ξ 1 , ξ 2 ) = G 1 (ξ 1 )G 2 (ξ 2 ); upon substitution in (65), we obtain the following.…”