# Loop quantum cosmology from an alternative Hamiltonian

## TL;DR

This paper introduces a novel Hamiltonian constraint operator in loop quantum cosmology using the Chern-Simons action, leading to a quantum bounce replacing the big bang and suggesting a transition to an asymptotic de Sitter universe.

## Contribution

It constructs an alternative Hamiltonian constraint operator in loop quantum cosmology based on the Chern-Simons action, providing new insights into quantum dynamics and cosmological evolution.

## Key findings

- Quantum bounce replaces classical big bang singularity.
- Effective Hamiltonian indicates a transition to de Sitter universe.
- Semiclassical analysis confirms correct classical limit.

## Abstract

In this paper, a new Hamiltonian constraint operator for loop quantum cosmology is constructed by using the Chern-Simons action. The quantum dynamics of the $k=0$ cosmological model with respect to a massless scalar field as an emergent time is determined by a difference equation. The semiclassical analysis shows that the new quantum dynamics has the correct classical limit, and the classical big-bang singularity is again replaced by the quantum bounce. Interestingly, the inverse time evolution of the flat Friedmann-Robertson-Walker cosmological model determined by the effective Hamiltonian will be bounced to an asymptotic de Sitter universe.