A Comment on Self-Tuning and Vanishing Cosmological Constant in the Brane World

TL;DR

This paper discusses mechanisms in brane world models that address the cosmological constant problem, highlighting non-local cancellation effects and potential fine-tuning issues in five-dimensional theories.

Contribution

It provides an analysis of how vacuum energy cancellation occurs in 5D brane systems and explores the implications of hidden fine-tuning in these models.

Findings

Non-local cancellation of vacuum energy between brane and singularities

Existence of hidden fine-tuning in brane world solutions

Insights into effective 4D cosmological constant in 5D frameworks

Abstract

In this note we elaborate on various five dimensional contributions to the effective 4D cosmological constant in brane systems. In solutions with vanishing 5D cosmological constant we describe a non-local mechanism of cancellation of vacuum energy between the brane and the singularities. We comment on a hidden fine tuning which is implied by this observation.