Attractors in $f(Q,B)$-gravity

TL;DR

This paper studies the long-term behavior of cosmological models in a modified gravity theory, identifying conditions for accelerated expansion and avoiding singularities through phase-space constraints.

Contribution

It introduces a detailed analysis of attractors in $f(Q,B)$-gravity, revealing parameter constraints for acceleration and singularity avoidance.

Findings

Existence of attractors corresponding to accelerated expansion.

Identification of asymptotic Big Rip and Big Crunch solutions.

Phase-space conditions necessary to prevent singularities.

Abstract

We investigate the asymptotic behavior of the cosmological field equations in Symmetric Teleparallel General Relativity, where a nonlinear function of the boundary term is introduced instead of the cosmological constant to describe the acceleration phase of the universe. Our analysis reveals constraints on the free parameters necessary for the existence of an attractor that accurately represents acceleration. However, we also identify asymptotic solutions depicting Big Rip and Big Crunch singularities. To avoid these solutions, we must impose constraints on the phase-space, requiring specific initial conditions.