Rotating cosmologies: classical and quantum

TL;DR

This paper explores rotating, anisotropic cosmologies with solid matter, revealing new conserved quantities and examining their classical and quantum properties within a minisuperspace framework.

Contribution

It introduces a new class of rotating cosmologies driven by solid matter and analyzes their symmetries and conservation laws in the minisuperspace approach.

Findings

Rotating cosmologies characterized by conserved angular momentum.

Solid inflation shows slow decay of anisotropies.

Quantum cosmology questions related to spacetime symmetries are better defined for solid-driven models.

Abstract

We revisit spatially flat, anisotropic cosmologies within the framework of mini-superspace. Putting special emphasis on the symmetries of the mini-superspace action and on the associated conservation laws, we unveil a new class of rotating cosmologies driven by solid matter. Their rotating is physical, in that it is characterized in an invariant way in terms of a conserved angular momentum. Along the way, we confirm the results of Bartolo et al. regarding the slow decay of anisotropies for solid inflation. We then use our minisuperspace approach as a laboratory to address certain puzzles of quantum cosmology-among these, how to characterize the spacetime symmetries of a quantum state at the level of the wavefunction of the universe. For the case of a solid driven cosmology, this question seems better defined than in more standard cases. Other questions remain unanswered, though; in particular, the general question of how to operate a minisuperspace-like truncation of degrees of freedom that is consistent at the quantum level.