Effective Improved-GUP Cosmology: Emergent FLRW Universe without a Bounce

TL;DR

This paper explores a GUP-inspired quantum gravity model that replaces the Big Bang singularity with a non-singular, emergent universe, ensuring a maximum energy density and faster classicalization.

Contribution

It introduces an improved scheme with a variable GUP parameter that resolves fiducial anomalies and maintains an emergent universe without a bounce.

Findings

Replaces classical singularity with a non-singular emergent universe.

Introduces an improved scheme with inverse proportional GUP parameter.

Achieves a universal maximum energy density and faster classicalization.

Abstract

We investigate the effective dynamics of a spatially flat FLRW universe coupled to a massless scalar field by applying the improved generalized uncertainty principle (GUP)-inspired deformations to the algebra of Ashtekar-Barbero variables. We consider deformations, once only in the geometry sector, and once in both the geometry and matter sectors. We show that in both cases, the classical singularity is replaced with a non-singular, emergent universe coasting from a constant-volume state in the infinite relational past time without a bounce. As expected, a constant geometric GUP parameter leads to fiducial anomalies, but we resolve it by employing an improved scheme in which this parameter is inversely proportional to the gravitational momentum. This leads to a universal, invariant maximum energy density while preserving the emergent nature of the universe. A Lyapunov stability analysis reveals that the improved scheme drives the universe toward classicality faster than the constant scheme.