Sudden future singularities in FLRW cosmologies

TL;DR

This paper investigates sudden future singularities in FLRW cosmologies, revealing they can meet some energy conditions but always violate the dominant energy condition, implying divergent energy fluxes.

Contribution

It provides a model-independent analysis showing that FLRW cosmologies with sudden singularities violate the dominant energy condition, highlighting fundamental physical constraints.

Findings

Sudden future singularities can satisfy null, weak, and strong energy conditions.

Such cosmologies always violate the dominant energy condition.

They require divergent spacelike energy fluxes in all but the comoving frame.

Abstract

The standard energy conditions of classical general relativity are applied to FLRW cosmologies containing sudden future singularities. Here we show, in a model independent way, that although such cosmologies can satisfy the null, weak and strong energy conditions, they always fail to satisfy the dominant energy condition. They require a divergent spacelike energy flux in all but the comoving frame.