Published online by Cambridge University Press: 01 January 2022
We make two points about dualities in string theory. The first point is that the conception of duality, which we will discuss, meshes with two dual theories being ‘gauge related’ in the general philosophical sense of being physically equivalent. The second point is a result about gauge/gravity duality that shows its relation to gauge symmetries to be subtler than one might expect: each of a certain class of gauge symmetries in the gravity theory, that is, diffeomorphisms, is related to a position-dependent symmetry of the gauge theory.
We thank various audiences, especially the audience at PSA 2014, and two referees. Nicholas Teh thanks the John Templeton Foundation for supporting his work on this article.