String theory T-duality and the zero point length of spacetime

TL;DR

This paper demonstrates through explicit path integral calculations that string theory's T-duality naturally leads to a zero-point length in spacetime, supporting the idea that quantum gravity acts as a UV regulator.

Contribution

It provides the first explicit derivation showing that string theory's T-duality results in a zero-point length, aligning with previous hypotheses about path integral duality.

Findings

String theory's T-duality induces a zero-point length in spacetime.

The lowest order string correction matches the path integral duality hypothesis.

Supports the view that quantum gravity acts as a UV regulator.

Abstract

It has been often conjectured that the correct theory of quantum gravity will act as a UV regulator in the low energy limit of quantum field theory. Earlier work has shown that if the path integral defining the quantum field theory propagator is modified, so that the amplitude is invariant under the duality transformation l--> 1/l where l is the length of the path, then the propagator is UV-finite and exhibits a ``zero-point length'' of the spacetime. Since string theory uses extended structures and has a T-duality, these results should also emerge directly from string theory. We show, by explicit path integral computation, that this is indeed the case. The lowest order string theory correction to the propagator is the same as that obtained by the hypothesis of path integral duality.