We study a theory of particles interacting with strings. Considering such a theory for Type IIA superstring will give some clue about M-theory. As a first step toward such a theory, we construct the particle-particle-string interaction vertex generalizing the D-particle boundary state.
A pedagogical introduction to the theory of supermembrane was delivered with a strong hope that this theory will play an essential role in the non-perturbative unification of string theories. Only a brief summary of the talk is given.
After a short review of the U-duality transformation of type II superstrings, we propose a mass formula for the BPS states which is invariant under U-transformation. This formula is consistent with the Dirac-Born-Infeld action for the Dirichlet brane.
A review of the nonlinear realization in supersymmetric theory is presented. The basic theory by Bando, Kuramoto, Maskawa and Uehara is explained in a pedagogical way. We shall also present a bit detailed exlanation of the superconformal tensor calculus of supergravity in connection with the coupling of the nonlinear sigma model to supergravity.
In the lectures given at '96 Kashikojima Summer Institute, Amagi-Highland Seminars, and Yukawa Institute Workshop, the old-fashioned dualities and the theory of extended objects are reviewed, starting from 't Hooft-Mandelstam duality and following the author's old works. Application of the old-fashioned dualities to new issues are also given on the D-branes, on the phase transition of B-F theory to Einstein gravity and on the swimming of microorganisms.
Starting from the gauge hierarchy problem as a motivation, supersymmetric theories are reviewed with particular emphasis on models with supersymmetry breaking. After reviewing the fundamentals of SUSY field theories, recent progress on nonperturbative dynamics of SUSY gauge theories is briefly summarized. Folklore of dynamical SUSY breaking is mentioned and new mechanisms are introduced. Finally concrete models of dynamical SUSY breaking are reviewed. Possible problems are also considered.