A Comment on the Cosmological Constant Problem in Spontaneously Broken Supergravity

TL;DR

This paper discusses how the small cosmological constant in supergravity models relates to the absence of specific operators in an inverse Planck mass expansion, offering a new perspective on the fine-tuning problem.

Contribution

It introduces a novel expansion approach in supergravity that links the vanishing cosmological constant to the absence of certain operators, simplifying effective field theory analysis.

Findings

The vanishing of the cosmological constant correlates with missing operators in the expansion.

The proposed expansion simplifies the analysis of spontaneously broken supergravity models.

It suggests potential underlying principles for the smallness of the cosmological constant.

Abstract

In spontaneously broken supergravity with non-flat potential the vanishing of the cosmological constant is usually associated with a non-trivial balancing of two opposite-sign contributions. We make the simple observation that, in an appropriately defined expansion of the superfield action in inverse powers of $M_P$, this tuning corresponds to the absence of two specific operators. It is then tempting to speculate what kind of non-standard symmetry or structural principle might underlie the observed extreme smallness of the corresponding coefficients in the real world. Independently of such speculations, the suggested expansion appears to be a particularly simple and convenient starting point for the effective field theory analysis of spontaneously broken supergravity models.