Professor Ruehle’s main research interest is string theory, but he works also on mathematical and computational aspects of physics, theoretical particle physics and cosmology.

String theory is one of the most promising candidates for a UV-complete theory of quantum gravity. The theory is highly constrained by mathematical and physical consistency conditions. One of these constraints imposes that our spacetime is ten-dimensional. In order to make contact with our observed universe, it is assumed that six extra spatial directions are small and thus evade detection.

Interestingly, string theory in 10 dimensions is almost unique. So all observable physics is encoded in the properties of the compact dimensions. Studying these properties requires tools in mathematics (algebraic geometry and commutative algebra). However, exact symbolic solutions to some string theory equations are unknown. This can be because mathematics is not yet advanced enough to deal with them or because finding solutions is so hard (from a computational complexity point of view) that it cannot be done in practice. In either case, methods from numerical mathematics, data science, artificial intelligence and machine learning can help to find (or approximate) solutions.