This study demonstrates that the zeros of diagonal components Green functions are key quantities can detect noninteracting topological insulators. We show traverse band gap in phases. The traverses induce crosses zeros, and zeros' surface gap, analogous to Fermi metals. By calculating microscopic models, we universally appear all six classes conventional utilizing eigenvector-eigenvalue identit...

We present a new method for calculating the Green functions for a lattice scalar field theory in D dimensions with arbitrary potential V (φ). The method for non-perturbative evaluation of Green functions for D=1 is generalized to higher dimensions. We define “hole functions” A (i = 0, 1, 2, · · · , N−1) from which one can construct N -point Green functions. We derive characteristic equations of...

Using the method of correlation dynamics we investigate the properties of a field-theory for fermions and scalar bosons coupled via a Yukawa interaction. Within this approach, which consists in an expansion of full equal-time Green functions into connected equal-time Green functions and a corresponding trun-cation of the hierarchy of equations of motion we carry out calculations up to 4th order...

Dyadic Green functions for time–harmonic fields in a homogeneous, isotropic, dielectric– magnetic medium, moving with constant velocity, are derived by first implementing a simple transformation and then using the dyadic Green functions available for uniaxial dielectric–magnetic mediums.