# Gauge-invariant bounce from loop quantum gravity

## TL;DR

This paper develops a gauge-invariant approach in loop quantum gravity that reveals a non-singular, asymmetric bounce replacing the big bang, with novel effects on effective constants and matter behavior near the bounce.

## Contribution

It introduces a gauge-invariant framework for singularity resolution in loop quantum gravity, uncovering new features of quantum geometry and matter interactions at the bounce.

## Key findings

- Quantum geometric effects replace the big bang with a non-singular bounce.
- The bounce is generically asymmetric, with rescaled constants.
- Near the bounce, matter exhibits non-minimal coupling behavior.

## Abstract

We present a gauge-invariant treatment of singularity resolution using loop quantum gravity techniques with respect to local SU(2) transformations. Our analysis reveals many novel features of quantum geometry which were till now hidden in models based on non-gauge-invariant discretizations. Quantum geometric effects resolve the big bang singularity replacing it with a non-singular bounce when spacetime curvature reaches Planckian value. The bounce is found to be generically asymmetric in the sense that pre-bounce and post-bounce branches are not mirrored to each other and effective constants, such as Newton's constant, are rescaled across the bounce. Furthermore, in the vicinity of the bounce, minimally coupled matter behaves as non-minimally coupled. These ramifications of quantum geometry open a rich avenue for potential phenomenological signatures.