Quantum statistical field theory : an introduction to Schwingers variational method with Greens function nanoapplications graphene and superconductivity Dirac notation and transformation theory Identical particles and second quantization: occupation number representation Q.M. pictures; Heisenberg equation; linear response; superoperators and non Markovian equations Schwinger action principle and variational calculus Retarded Greens functions Quantum mechanical ensemble averages and statistical thermodynamics Thermodynamic Greens functions and spectral structure Equations of motion with particle particle interactions and approximations Non equilibrium Greens functions: variational relations and approximations for particle interactions Random phase approximation plasma phenomenology semiclassical and hydrodynamic models; electrodynamics Interacting electron hole phonon system Graphene Superfluidity and superconductivity Epilogue