Thomas F George & Renat R Letfullin 
Theoretical Physics and Nonlinear Optics 
Theories and Models

This book presents research in the field of theoretical physics and nonlinear optics. Topics discussed include quantum field theory; higher dimensional model spaces and defects; non-linear refractive index theory; quark-pion coupling constant and ground-state baryon masses; the search for higgs bosons in two-higgs doublet models and the neutrino mass in a six dimensional E6 model.