I have performed research on a broad spectrum of problems in theoretical physics. My focus has been on applications of quantum field theory in fields like high energy physics, condensed matter theory and the physics of the early universe. In particular I have been concerned with topological aspects of nonlinear systems, i.e. topological excitations like non abeleian vortices, domain walls, monopoles, skyrmions and instantons and their moduli spaces. I did pioneering research two dimensional systems which exhibit topological order leading to the existence of anyons which are particle like collective excitations which exhibit very exotic spin and braid statistics properties. These anyons allow for an implementation of quantum computation that is intrinsically decoherence free. This approach also allows new answers to conceptual questions about key systems like two dimensional quantum gravity and duality in supersymetric gauge theories. I wrote some popular books on science that have been translated in some 15 languages.