Cosmological Evolution of Equation of State for Dark Energy in G-Essence Models

Abstract

We explore the cosmological evolution of equation of state (EoS) for dark energy in g-essence models, the action of which is described by a function of both the canonical kinetic term of both the scalar and fermionic fields. We examine g-essence models with realizing the crossing of the phantom divide line of w DE = −1 as well as the models in which the universe always stays in the non-phantom (quintessence) phase (w DE > −1). In particular, we find an explicit g-essence model with the crossing from the non-phantom phase to the phantom one (w DE < −1). This transition behavior is consistent with the recent observational data analyses.

Cosmographic analysis of a model of the pulsating universe with diverse types of matter

“…Эффективность космографии состоит в том, что она дает возможность тестировать любые космологические модели, не противоречащие космологическому принципу [38]. Разложение масштабного фактора в ряд Тейлора в окрестностях текущего момента времени 𝑡 0 приводит к выражению, которое зависит только от метрики (9) и полностью независит от модели [39][40].…”

Inflation from the Symmetry of the Generalized Cosmological Model

“…Here, to generalize the influence of the scalar field on the cosmological model, we use the k-essence model with the Lagrangian density in generalized form L = F(φ, X) [3,4] based on the k-inflation model [5]. We do not consider other forms of fields here, like tachyon field, phantom (ghost) field, dilatonic dark energy, Chaplygin gas, or generalisation of scalar and fermion fields g-essence [6][7][8].…”

Gravitational Baryogenesis in Hořava–Lifshitz gravity

“…In the scalar field models φ is assumed to be spatially homogeneous, φ2 /2 is the kinetic energy and V (φ) is the potential energy [22]. Scalar field models of DE have been discussed in [23][24][25][26]. Chaplygin gas model [27,28] is another form of dark energy proposed in literature.…”