1,539 research outputs found
Quantum Statistical Field Theory and Combinatorics
This is a set of review notes on combinatorial aspects of Bosonic quantum
field theory. We collect together several related issues concerning moments of
distributions, moments of stochastic processes and Ito's formula, and Green's
functions and cumulant moments in quantum field theory.Comment: 50 pages, several figures, extended notes with up-dated reference
Stochastic Schrodinger equations as limit of discrete filtering
We consider an open model possessing a Markovian quantum stochastic limit and
derive the limit stochastic Schrodinger equations for the wave function
conditioned on indirect observations using only the von Neumann projection
postulate. We show that the diffusion (Gaussian) situation is universal as a
result of the central limit theorem with the quantum jump (Poissonian)
situation being an exceptional case. It is shown that, starting from the
correponding limiting open systems dynamics, the theory of quantum filtering
leads to the same equations, therefore establishing consistency of the quantum
stochastic approach for limiting Markovian models.Comment: 21 pages, no figure
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