The little sibling of the big rip singularity

TL;DR

This paper introduces the 'little sibling of the big rip,' a smoother cosmological singularity where the Hubble rate diverges but the cosmic derivative remains finite, leading to universe destruction in finite time despite appearing benign.

Contribution

It proposes a new cosmological event, the little sibling of the big rip, which differs from traditional singularities by its milder divergence properties and implications for universe fate.

Findings

The Hubble rate and scale factor blow up at the event.

Bound structures are destroyed in finite cosmic time.

The model mimics a ΛCDM universe at present.

Abstract

We present a new cosmological event, which we named the little sibling of the big rip. This event is much smoother than the big rip singularity. When the little sibling of the big rip is reached, the Hubble rate and the scale factor blow up but the cosmic derivative of the Hubble rate does not. This abrupt event takes place at an infinite cosmic time where the scalar curvature explodes. We show that a doomsday \'a la little sibling of the big rip is compatible with an accelerating universe, indeed at present it would mimic perfectly a LCDM scenario. It turns out that eventhough the event seems to be harmless as it takes place in the infinite future, the bound structures in the universe would be unavoidably destroyed on a finite cosmic time from now. The model can be motivated by considering that the weak energy condition should not be abusibely violated in our Universe, and it could give us some hints about the status of recently formulated nonlinear energy conditions.