Dynamical system analysis of Myrzakulov gravity

TL;DR

This paper analyzes the dynamical behavior of Myrzakulov gravity, a modified gravity theory with non-zero curvature and torsion, revealing diverse late-time cosmological scenarios including dark energy dominance and phantom crossing.

Contribution

It provides a detailed dynamical system analysis of Myrzakulov gravity models, identifying critical points and stability, and exploring their cosmological implications.

Findings

Class 1 models exhibit ΛCDM-like behavior with matter and dark energy eras.

Dark energy behaves as a cosmological constant at late times.

Class 2 models show richer behavior, including quintessence, phantom, and crossing scenarios.

Abstract

We perform a dynamical system analysis of Myrzakulov or F(R, T) gravity, which is a subclass of affinely connected metric theories, where ones uses a specific but non-special connection, which allows for non-zero curvature and torsion simultaneously. We consider two classes of models, we extract the critical points, and we examine their stability properties alongside their physical features. In the Class 1 models, which possess {\Lambda}CDM cosmology as a limit, we find the sequence of matter and dark energy eras, and we show that the Universe will result in a dark-energy dominated critical point for which dark energy behaves like a cosmological constant. Concerning the dark-energy equation-of-state parameter we find that it lies in the quintessence or phantom regime, according to the value of the model parameter. For the Class 2 models, we again find the dark-energy dominated, de Sitter late-time attractor, although the scenario does not possess {\Lambda}CDM cosmology as a limit. The cosmological behavior is richer, and the dark-energy sector can be quintessence-like, phantom-like, or experience the phantom-divide crossing during the evolution.