# Selberg trace formula
The Selberg trace formula was discovered by the Norwegian mathematician Atle Selberg in the 1950s. It provides a deep connection between the geometry of Riemann surfaces and the spectra of differential operators (such as the Laplacian) defined on them.
For interacting field theories, we have a generalisation called the Gutzwiller trace formula. In systems exhibiting geodesic motion on hyperbolic surfaces, the Gutzwiller
trace formula agrees with the Selberg trace formula.
## Refs
- original
- [[1957#Selberg]]
- interacting fields
- [[1970#Gutzwiller]]
- [[1971#Gutzwiller]]
- see also a book by Gutzwiller: Chaos in Classical and Quantum Mechanics, Chapter 17