One loop superstring effective actions and d=4 supergravity

TL;DR

This paper reviews recent findings on a new R^4 term at one loop in type IIA and heterotic string effective actions reduced to four dimensions, exploring its supersymmetrization and implications for supergravity.

Contribution

It identifies a new independent R^4 term at one loop in four-dimensional effective actions, expanding understanding of string theory corrections.

Findings

Discovery of a new R^4 term at one loop in 4D effective actions

Analysis of supersymmetrization of the new R^4 term

Comparison with the square of the Bel-Robinson tensor

Abstract

We review our recent work on the existence of a new independent R^4 term, at one loop, in the type IIA and heterotic effective actions, after reduction to four dimensions, besides the usual square of the Bel-Robinson tensor. We discuss its supersymmetrization.