# Configurational entropy and instability of tachyonic braneworld

## TL;DR

This paper investigates the configurational entropy of tachyonic braneworlds with different cosmological constants, revealing critical values linked to universe acceleration and stability under scalar perturbations.

## Contribution

It introduces a detailed analysis of configurational entropy in tachyonic braneworlds with various cosmological constants, including exact solutions and stability conditions.

## Key findings

- Global minimum of entropy at critical scale factor for negative/zero cosmological constant
- Monotonically decreasing entropy with positive cosmological constant
- Stability of the system under scalar perturbations for negative/zero cosmological constant

## Abstract

We consider tachyonic braneworld with a bulk cosmological constant and investigate a configurational entropy of various magnitudes of scale factor. It is found that for a bulk negative/zero cosmological constant, the configurational entropy has a global minimum when the magnitude of scale factor reaches the critical value. This result seems to have intriguing implications such that an accelerated rate of the universe and cosmological inflation rate for radiation/matter domination are able to be determined by such critical value. We also find that the configurational entropy almost monotonically decreases for a bulk positive cosmological constant as the magnitude of scale factor grows up. We find an exact solution of tachyonic braneworld in a bulk de Sitter space. It is shown that such system under scalar perturbations is stable for some constraint relation. Furthermore, we also find that tachyonic braneworld model with a bulk negative/zero cosmological constant is always stable under scalar perturbations.