In this seminar we shall discuss the issue of duality transformation in the context of f topological mass generation in diverse dimensions. Particular emphasis will be given to the mass generation mechanism as the result of interference between self and anti self-dual components, as disclosed by the soldering formalism. Since this is a gauge embedding procedure derived from an old algorithm of second-class constraint conversion used by the author to approach anomalous gauge theories, a quick review of the subject will be presented. The problem of classification of the electromagnetic duality groups that is closely related will also be briefly discussed. Particular emphasis will be given to a new approach to duality based on the soldering embedding to tackle to problem of mass generation by topological mechanisms in D=3 and D=4 dimensions including the couplings to dynamical matter and nonlinear cases.
