QM Research Seminar: Probing the quantum gravity landscape with faithful strings

Speaker: ​Guglielmo Lockhart (University of Bonn).

​Abstract: 
General principles suggest that the spectrum of excitations of quantum gravity theories includes not just pointlike particles, but also higher-dimensional membranes. In this talk I will focus on a specific class of one-dimensional membranes, the faithful strings, whose properties can be described using the language of vertex operator algebras. I will discuss how this mathematical structure encodes symmetries of quantum gravity theories, and makes it possible to determine refined information like gauge group topology. Moreover, I will show that modular invariance of the faithful string torus partition function is a powerful tool to detect inconsistencies in a candidate quantum gravity theory, or conversely to identify apparently consistent quantum gravities and study their properties. This provides an exciting opportunity to study exotic quantum gravity models that do not admit any known weakly coupled realization within string theory, in supersymmetric as well as non-supersymmetric settings.