More on Bianchi I spacetimes and f(T) gravity

TL;DR

This paper investigates Bianchi I cosmological solutions within f(T) gravity, highlighting their analytical tractability and the unpredictability of the teleparallel connection due to arbitrary spatial rotations of tetrads.

Contribution

It demonstrates the analytical solvability of Bianchi I solutions in f(T) gravity and reveals the issue of connection unpredictability caused by tetrad rotations.

Findings

Analytical solutions for Bianchi I spacetimes in f(T) gravity.

Unpredictability of the teleparallel connection under spatial rotations.

Applicability to simple Friedmann universes.

Abstract

Bianchi I cosmological solutions in f(T) gravity are discussed. We start from diagonal metrics and tetrads and show that their dynamical equations are pretty much tractable analytically, with a possible arena for physical applications. Then we derive a very bad unpredictability of the teleparallel connection in these configurations. Namely, even for the simple isotropic Friedmann universes, one might apply an arbitrary time-dependent spatial rotation to the standard tetrad without changing anything in the cosmological equations.