The Green function for Klein-Gordon-Dirac equation is obtained. The case with the dominating Klein-Gordon term is considered. There seems to be a formal analogy between our problem and a certain problem for a 4-dimensional particle moving in the external field. The explicit relations between the wave function, Green function and initial conditions are established with the help of the T -exponen...

Uni6n M a t d t i c a Argentina Vol. 35 1990. Introduction The main purpose of this paper is to give a comprehensive motivation, with most of the key ideas used in the recent work by Garroni and Menaldi [lo], on the construction of the Green function G(z, t, (, r) for an integro-differential initial boundary value problem, when the differential operator is a second-order parabolic operator not ...

A mathematic model of Green function is build for two dimension free water surface. The analytic expression of Green function is obtained by introducing a parameter of complex number. The intrinsic properties of Green function are discussed for the special parameter values. The real and imaginary parts of H function are shown in the paper.

The single-particle nuclear potential is intrinsically nonlocal. In this paper, we consider nonlocalities which arise from the many-body and fermionic nature of the nucleus. We investigate the effects of nonlocality in the nuclear potential by developing the Green’s function for nonlocal potentials. The formal Green’s function integral is solved analytically in two different limits of the wavel...

A new method for the stabilization of the sign problem in the Green Function Monte Carlo technique is proposed. The method is devised for real lattice Hamiltonians and is based on an iterative ”stochastic reconfiguration” scheme which introduces some bias but allows a stable simulation with constant sign. The systematic reduction of this bias is in principle possible. The method is applied to t...

Green function (which can be called the q-analogous of the Hankel function) on the quantum plane E q = Eq(2)/U(1) is constructed.

*Correspondence: Colin J. R. Sheppard, Department of Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy e-mail: [email protected] We review Fourier methods used in the disciplines of electromagnetism and signal processing, with a view to reconciling differences in approach. In particular, Fourier methods well known in signal processing are applied to three-...

In this chapter we introduce the fundamental concepts behind the Green Function Theory. We start from a description of the second quantization method and then, after introducing the ensemble average of an operator, we define the main object of the theory, the Green function. Further on, after obtaining the equation of motion for the Green function, we introduce the self-energy operator and we d...

This paper derives, in closed form, the Green function of an FEL operating in the strongly Raman regime. This Green function allows for the calculation of the temporal and spatial evolution of an arbitrary input radiation pulse. For the first time superradiance, originally studied in Compton regime by Bonifacio and co-workers [Phys. Rev. Lett. 73 (1994) 70; Nucl. Instr. and Meth. A 239 (1985) 3...