String-inspired infinite-derivative theories of gravity: A brief overview

Abstract

In String Theory, there often appears a rather interesting class of higher derivative theories containing an infinite set of derivatives in the form of an exponential. These theories may provide a way to tame ultraviolet (UV) divergences without introducing ghost-like states. Here we provide a brief overview on the progress that has been made over the last decade to construct such infinite-derivative theories of gravity (IDG) which may be able to address the singularity problems in gravity. In the process, we will present some general results that applies to covariant torsion-free metric theories of gravity.