Dominant Energy Condition and dissipative fluids in general relativity

TL;DR

This paper critiques the use of the Dominant Energy Condition in dissipative fluids within general relativity, highlighting its failure to prevent superluminal flows and comparing with tilted perfect fluids.

Contribution

It reveals limitations of the Dominant Energy Condition for dissipative fluids and discusses tilted perfect fluids for comparison.

Findings

The Dominant Energy Condition does not prevent superluminal flows in dissipative fluids.

Tilted perfect fluids have stress-energy tensors similar to imperfect fluids.

The paper clarifies the conditions under which energy constraints are valid in general relativity.

Abstract

Existing literature implements the Dominant Energy Condition for dissipative fluids in general relativity. It is pointed out that this condition fails to forbid superluminal flows, which is what it is ultimately supposed to do. Tilted perfect fluids, which formally have the stress-energy tensor of imperfect fluids, are discussed for comparison.