# BRS structure of Simple Model of Cosmological Constant and Cosmology

## TL;DR

This paper analyzes a topological field theory model addressing the cosmological constant problem, identifying a unique unbroken BRS symmetry, and demonstrating a stable de Sitter solution consistent with universe acceleration.

## Contribution

It reveals the existence of a single unbroken BRS symmetry in the model and explores its implications for cosmology and the universe's accelerating expansion.

## Key findings

- One unbroken BRS symmetry guarantees unitarity.
- The model reduces the quantum vacuum energy problem to initial condition selection.
- A stable de Sitter solution explains current cosmic acceleration.

## Abstract

In arXiv:1601.02203, a simple model has been proposed in order to solve one of the problems related with the cosmological constant. The model is given by a topological field theory and the model has an infinite numbers of the BRS symmetries. The BRS symmetries are, however, spontaneously broken in general. In this paper, we investigate the BRS symmetry in more details and show that there is one and only one BRS symmetry which is not broken and the unitarity can be guaranteed. In the model, the quantum problem of the vacuum energy, which may be identified with the cosmological constant, reduces to the classical problem of the initial condition. In this paper, we investigate the cosmology given by the model and specify the region of the initial conditions which could be consistent with the evolution of the universe. We also show that there is a stable solution describing the de Sitter space-time, which may explain the accelerating expansion in the current universe.