... of atomic physics, condensed matter physics andchemistry. It furthermore plays a fundamental role in the studies of the nature of starsand of the scattering processes in high energy physics. ... |ψ, and we concludeν|νν| = 1. (1.7)Introduction toMany-body quantum theory in condensed matter physics Henrik Bruus and Karsten FlensbergØrsted Laboratory, Niels Bohr Institute, University ... have today describing the physics of energy and matter. It has successfully been applied to explain phenomenaranging over many orders of magnitude, from the study of elementary particles on thesub-nucleonic...