Wilsonian Effective Field Theory and String Theory

TL;DR

This paper discusses how deriving effective field theories from string theory requires a Wilsonian approach with a physical cutoff, highlighting differences in regularization methods and implications for the cosmological constant problem.

Contribution

It introduces a Wilsonian perspective with proper time regularization in string theory, contrasting it with dimensional regularization and exploring implications for the cosmological constant.

Findings

Proper time regularization demonstrates state decoupling in string theory.

A negative UV cosmological constant does not necessarily imply a negative IR cosmological constant.

Implications for swampland conjectures and criteria for positive cosmological constant.

Abstract

We argue that deriving an effective field theory from string theory requires a Wilsonian perspective with a physical cutoff. Employing proper time regularization we demonstrate the decoupling of states and contrast this with what happens in dimensional regularization. In particular we point out that even if the cosmological constant (CC) calculated from some classical action at some ultra-violet scale is negative, this does not necessarily imply that the CC calculated at cosmological scales is also negative, and discuss the possible criteria for achieving a positive CC starting with a CC at the string/KK scale which is negative. Obviously this has implications for swampland claims.