On the causality aspects of the dynamical Chern-Simons modified gravity

TL;DR

This paper investigates G"{o}del-type solutions in dynamical Chern-Simons gravity, demonstrating the existence of causal solutions in vacuum and with various matter fields, highlighting differences from non-dynamical models.

Contribution

It shows that dynamical Chern-Simons gravity admits causal G"{o}del-type solutions in vacuum and with different matter contents, unlike non-dynamical frameworks.

Findings

Causal solutions exist in vacuum within dynamical Chern-Simons gravity.

Causal solutions are possible for various matter fields including fluids and electromagnetic fields.

Dynamical framework allows for causality where non-dynamical models do not.

Abstract

We discuss the G\"{o}del-type solutions within the dynamical Chern-Simons modified gravity in four dimensions. Within our study, we show that in the vacuum case the causal solutions are possible which cannot take place within the non-dynamical framework. Another our result consists in the possibility for completely causal solutions for all types of matters we study in the paper, that is, relativistic fluid, cosmological constant, scalar and electromagnetic fields.