The members of the theoretical particle physics group are involved in a variety of problems in particle phenomenology, gravitation, and quantum field theory. Field theoretical aspects that are covered include lattice field theory, renormalization group techniques, classical and quantum gravity as related to string theories, and various applications of the theory of group representations. Combinations of analytical and numerical techniques are used, including symbolic manipulations and numerical integration on the high energy group's computers. The renormalization group method is an essential tool to understand and describe the large distance behavior of gauge theories and spin models. Various semi-analytical tools to be used in conjunction with this method are being developed.
Emphasis is put on accuracy and comparison with series expansions.
Applications include upper bounds on the Higgs mass. Other theoretical studies of gauge and gravitational theories in the non-perturbative regime include the use of geometry and topology. Theoretical physicists and mathematicians meet weekly for a joint seminar. Topics discussed involve ergodic problems, quantum chaos, and the theory of group representation. A seminar series on topics of interest to theoretical and experimental particle and nuclear physics also meets weekly.