Scalar Field Kantowski--Sachs Solutions in Teleparallel $F(T)$ Gravity

TL;DR

This paper develops a general method to find new exact solutions in scalar field teleparallel $F(T)$ gravity with Kantowski--Sachs symmetry, potentially impacting cosmological models of dark energy and dark matter.

Contribution

It introduces a universal formula for deriving all possible $F(T)$ solutions with scalar fields, expanding the solution space for cosmological applications.

Findings

Derived new classes of exact $F(T)$ solutions.

Applicable to models of dark energy and phantom energy.

Provided a general formula for solution generation.

Abstract

In this paper, we investigate time-dependent Kantowski--Sachs spherically symmetric teleparallel $F(T)$ gravity with a scalar field source. We begin by setting the exact field equations to be solved and solve conservation laws for possible scalar field potential, $V\left(\phi\right)$, solutions. Then, we find new non-trivial teleparallel $F(T)$ solutions by using power-law and exponential ansatz for each potential case arising from conservation laws, such as linear, quadratic, or logarithmic, to name a few. We find a general formula allowing us to compute all possible new teleparallel $F(T)$ solutions applicable for any scalar field potential and ansatz. Then, we apply this formula and find a large number of exact and approximate new teleparallel $F(T)$ solutions for several types of cases. Some new $F(T)$ solution classes may be relevant for future cosmological applications, especially concerning dark matter, dark energy quintessence, phantom energy leading to the Big Rip event, and quintom models of physical processes.