Is string theory a theory of quantum gravity?

TL;DR

The paper discusses the challenges in developing a complete quantum theory of gravity, evaluating string theory's potential and limitations in addressing key issues like high-energy scattering and quantum cosmology.

Contribution

It critically examines the current status of string theory in solving fundamental quantum gravity problems and highlights the need for new ideas or frameworks.

Findings

String theory addresses some quantum gravity problems but remains inconclusive.

Key issues include unitarity in high-energy scattering and quantum cosmology.

Further mechanisms or frameworks may be necessary for progress.

Abstract

Some problems in finding a complete quantum theory incorporating gravity are discussed. One is that of giving a consistent unitary description of high-energy scattering. Another is that of giving a consistent quantum description of cosmology, with appropriate observables. While string theory addresses some problems of quantum gravity, its ability to resolve these remains unclear. Answers may require new mechanisms and constructs, whether within string theory, or in another framework.