Yorck Sommerhäuser

Assistant Professor of Mathematics

PhD Munich

Office: HH-3007
Phone: (709) 864-8097
Fax: (709) 864-3010


Personal Webpage

Dr. Sommerhäuser studied mathematics at the Universities of Bonn, Tübingen, and Munich. He received his doctorate from the University of Munich in 1999, where he afterwards took his first academic position as Wissenschaftlicher Assistent. Before coming to Memorial, Dr. Sommerhäuser held positions at the Hong Kong University of Science and Technology, the University of Cincinnati, the University of South Alabama, and SUNY Buffalo.

Dr. Sommerhäuser's research area is the theory of Hopf algebras, especially semisimple Hopf algebras. Key topics to which he and his coauthors have contributed include the construction of deformed enveloping algebras from Yetter-Drinfel'd Hopf algebras, Kaplansky's fifth conjecture on the involutivity of the antipode of a semisimple Hopf algebra in positive characteristic, the structure theory of Yetter-Drinfel'd Hopf algebras and its application to the classification of semisimple Hopf algebras of dimension pq, Cauchy's theorem for Hopf algebras, the theory of Frobenius-Schur indicators and their generalization to equivariant Frobenius-Schur indicators, and the congruence subgroup property of the action of the modular group on the center of a semisimple factorizable Hopf algebra. The results of this research have appeared in three research monographs and many research articles.

Dr. Sommerhäuser frequently presents at international conferences and other institutions. He has taught short lecture series and summer schools at the University of Almería, Kansas State University, and Nanjing University. Further research visits have led him, among many other places, to the Mathematical Sciences Research Institute in Berkeley, DePaul University in Chicago, and the University of Hamburg.