# Scale Symmetry and Weinberg's No-go Theorem in the Cosmological Constant Problem

## TL;DR

This paper completes Weinberg's no-go theorem proof for classical gravity with scale symmetry and proposes a scale-invariant regularization method as a plausible solution to the cosmological constant problem, addressing radiative instability.

## Contribution

It finalizes the proof of Weinberg's no-go theorem in the context of scale symmetry and introduces a scale-invariant regularization approach to resolve the cosmological constant problem.

## Key findings

- Proof of Weinberg's no-go theorem completed for scale symmetric classical gravity
- Scale-invariant regularization provides a plausible solution to the cosmological constant problem
- Addresses radiative instability of the cosmological constant

## Abstract

We complete the proof of Weinberg's no-go theorem on the cosmological constant problem in classical gravity when the theory has a (global) scale symmetry. Stimulated with this proof, we explore a solution to the cosmological constant problem by the help of renormalization group equations. We find that the manifestly scale invariant regularization method provides a physically plausible solution to the cosmological constant problem, in particular, to the issue of radiative instability of the cosmological constant.