Categorizing Different Approaches to the Cosmological Constant Problem

TL;DR

This paper categorizes various theoretical approaches to the cosmological constant problem, providing a comprehensive classification, analyzing their pros and cons, and introducing a novel symmetry-based approach involving real and imaginary spacetime.

Contribution

It offers the first systematic classification of existing proposals for the cosmological constant problem and introduces a new symmetry-based approach.

Findings

Identified five main schemes addressing the problem

Provided a code for referencing different mechanisms

Proposed a new approach based on a symmetry principle

Abstract

We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future reference. We find that they all can be classified into five different schemes of which we indicate the advantages and drawbacks. Besides, we add a new approach based on a symmetry principle mapping real to imaginary spacetime.