A Small Cosmological Constant from a Large Extra Dimension

TL;DR

This paper introduces a novel higher-dimensional model where the Standard Model vacuum energy warps extra dimensions, maintaining 4D flatness and potentially solving the Cosmological Constant Problem without fine-tuning.

Contribution

It presents a new extra-dimensional framework that preserves 4D flatness despite vacuum energy, with a classical higher-dimensional gravity treatment and quantum Standard Model fields.

Findings

4D flatness is maintained despite vacuum energy.

The model's curvature effectively cuts off the extra dimension.

Standard Model quantum effects do not disrupt flatness.

Abstract

We propose a new approach to the Cosmological Constant Problem which makes essential use of an extra dimension. A model is presented in which the Standard Model vacuum energy ``warps'' the higher-dimensional spacetime while preserving 4D flatness. We argue that the strong curvature region of our solutions may effectively cut off the size of the extra dimension, thereby giving rise to macroscopic 4D gravity without a cosmological constant. In our model, the higher-dimensional gravity dynamics is treated classically with carefully chosen couplings. Our treatment of the Standard Model is however fully quantum field-theoretic, and the 4D flatness of our solutions is robust against Standard Model quantum loops and changes to Standard Model couplings.