Bianchi I solutions of effective quadratic gravity

TL;DR

This paper presents numerical solutions for Bianchi I cosmological models within an effective quadratic gravity framework, revealing asymptotic behaviors including de Sitter, Minkowski, and singular solutions, extending previous isotropic results.

Contribution

It provides the first numerical solutions for anisotropic Bianchi I models in effective quadratic gravity, generalizing prior isotropic findings.

Findings

Solutions asymptote to de Sitter, Minkowski, or singular states

Numerical solutions are exact within machine precision

Extends previous isotropic models to anisotropic Bianchi I spaces

Abstract

It is believed that soon after the Planck time, Einstein's general relativity theory should be corrected to an effective quadratic theory. Numerical solutions for the anisotropic generalization of the Friedmann "flat" model $E^3$ for this effective gravity are given. It must be emphasized that although numeric, these solutions are exact in the sense that they depend only on the precision of the machine. The solutions are identified asymptotically in a certain sense. It is found solutions which asymptote de Sitter space, Minkowski space and a singularity. This work is a generalization for non diagonal spatial metrics of a previous result obtained by one of us and a collaborator for Bianchi $I$ spaces.