Positive Definite Gravitational Action, Cosmological Constant and Superstring Theory

TL;DR

This paper proposes a positive definite Euclidean gravitational action based on Einstein equations' universality, explores its implications for quantum gravity, and discusses its potential derivation from superstring theory, suggesting a zero cosmological constant.

Contribution

It introduces a new positive definite gravitational action and links it to superstring theory, offering insights into the cosmological constant problem.

Findings

The new action suggests the cosmological constant is probably zero.

Implications for quantum gravity are considered.

A scenario for deriving the action from superstring theory is discussed.

Abstract

We use the recently discovered universality of Einstein equations in the first order formalism to suggest a positive definite Euclidean action. Possible implications for quantum gravity are considered. We discuss the Hawking and Coleman approach to the vanishing of the cosmological constant by using the new action and find that the cosmological constant is probably zero. A possible scenario for obtaining such an action from superstring field theory is discussed.