Symmetry and structure: an overview

摘要

The many aspects of symmetry and reviewed as a unifying principle in science. Discrete symmetry groups dictate the structure of physical objects and continuous space-time sym- metries are the generators of special relativity and quantum operators. Internal symmetry and gauge invariance provide the basis of quantum theory and the electromagnetic field. Approci- mate global symmetries underpin the formulation of conservations and natural laws in terms of field densities and conserved currents.