Relativity symmetry and the structure of quantum theory William H Klink (University of Iowa USA) Wolfgang Schweiger (University of Graz Austria) ; Volume 2: Point form relativistic quantum mechanics This book covers relativistic quantum theory from the point of view of a particle theory based on the irreducible representations of the Poincarâe group the group that expresses the symmetry of Einstein relativity. There are several ways of formulating such a theory; this book develops what is called relativistic point form quantum mechanics which unlike quantum field theory deals with a fixed number of particles in a relativistically invariant way. A chapter is devoted to applications of point form quantum mechanics to nuclear physics.