Modeling effective FRW cosmologies with perfect fluids from states of the hybrid quantum Gowdy model

TL;DR

This paper develops approximation methods in hybrid quantum Gowdy models to produce solutions that mimic flat FRW cosmologies filled with various perfect fluids, despite underlying inhomogeneities.

Contribution

It introduces a novel approach to approximate solutions in the quantum Gowdy model that effectively behave like homogeneous FRW universes with different perfect fluids.

Findings

Successfully modeled effective perfect fluid behaviors including dust, radiation, and cosmological constant.

Provided a framework for deriving homogeneous cosmological dynamics from inhomogeneous quantum states.

Demonstrated the flexibility of hybrid quantization methods in cosmological modeling.

Abstract

We employ recently developed approximation methods in the hybrid quantization of the Gowdy $T^3$ model with linear polarization and a massless scalar field to obtain physically interesting solutions of this inhomogeneous cosmology. More specifically, we propose approximate solutions of the quantum Gowdy model constructed in such a way that, for the Hamiltonian constraint, they effectively behave as those corresponding to a flat homogeneous and isotropic universe filled with a perfect fluid, even though these quantum states are far from being homogeneous and isotropic. We analyze how one can get different perfect fluid effective behaviors, including the cases of dust, radiation, and cosmological constant.