Theory of Many-Boson Systems

A note on 2D focusing many-boson systems

We consider a 2D quantum system of N bosons in a trapping potential |x|, interacting via a pair potential of the form Nw(Nx). We show that for all 0 < β < (s + 1)/(s + 2), the leading order behavior of ground states of the many-body system is described in the large N limit by the corresponding cubic nonlinear Schrödinger energy functional. Our result covers the focusing case (w < 0) where even ...

Many-body theory of degenerate systems

The many-body theory of degenerate systems is described in detail. More generally, this theory applies to systems with an initial state that cannot be described by a single Slater determinant. The double-source (or closed-time-path) formalism of nonequilibrium quantum field theory is used to derive an expression for the average value of a product of interacting fields when the initial state is ...

Unified theory of quantum many-particle systems

Using eigen-functional bosonization method, we study quantum manyparticle systems, and show that the quantum many-particle problems end in to solve the differential equation of the phase fields which represent the particle correlation strength. Thus, the physical properties of these systems are completely determined by the differential equation of the phase fields. We mainly focus on the study ...

Many-body Scattering Theory of Electronic Systems

This work reviews recent advances in the analytical treatment of the continuum spectrum of correlated few-body non-relativistic Coulomb systems. The exactly solvable two-body problem serves as an introduction to the non-separable three-particle system. For the latter case we discuss the existence of an approximate separability of the long and the short-range dynamics which is exposed in an appr...

Many–body Theory of Non–equilibrium Systems