As a child, she went to a gymnasium in Basel and then studied at the
University of Basel, graduating in 1982 with a diploma directed by Heinz Huber "On finiteness of the isometry group of a compact negatively curved
Riemannian manifold". She received her PhD in 1988, from the same university, with a thesis entitled "On the volumes of hyperbolic polytopes in dimensions three and four". Her advisor was Hans-Christoph Im Hof. During the year 1983–84 she also studied at the
University of Grenoble (
Fourier Institute).
Her main research fields include hyperbolic geometry, geometric group theory, geometry of
discrete groups (especially
reflection groups,
Coxeter groups), convex and polyhedral geometry, volumes of hyperbolic polytopes, manifolds and polylogarithms. She does historical research into the works and life of
Ludwig Schläfli, a Swiss
geometer.[2]
Kellerhals, Ruth (1992). "On the volumes of hyperbolic 5-orthoschemes and the trilogarithm". Commentarii Mathematici Helvetici. 67: 648–663.
doi:
10.1007/BF02566523.
S2CID120505581.
Kellerhals, Ruth (1989). "On the volume of hyperbolic polyhedra". Mathematische Annalen. 285 (4): 541–569.
doi:
10.1007/BF01452047.
S2CID55942104.