Prof. Dr. Peter Koepke undertakes research in set theory and logic as a part of the Bonn Mathematical Logic Group.  He earned his Ph.D. in 1984 and Habilitation in 1990 at Freiburg University.   His specific research interests include axiomatic set theory, including infinitary combinatorics, forcing and core models, consistency strengths without the axiom of choice, large cardinals; constructibility theory, including ordinal computability theory and new fine structure theories;  descriptive set theory and infinitary game theory; and general logic, including automated theorem proving and proof checking, such as in the NAPROCHE natural language proof-checking system.

Professor Welch (Professor of Mathematical Logic, University of Bristol) conducts research on a broad selection of topics in mathematical and philosophical logic. In set theory, he is a leading researcher on the topics of fine structure and core models, problems concerning determinancy, large cardinals and strong axioms of infinity. He has worked in the philosophy of mathematics on the foundations of set theory and theories of truth. And he has been a central figure in the recently intensified work on infinitary models of computation.