A 1D bosonic many-body system, related to the Bose–Einstein condensation in atomic traps and periodic optical lattices, is described by a coherent state path integral of the grand canonical partition function. Since the interaction is given by a contact potential, as commonly applied in atomic...

We present a perturbation theory by extending a prescription due to Feynman for computing the probability density function for the random flight motion. The method can be applied to a wide variety of otherwise difficult circumstances. The series for the exact moments, if not the distribution...

Spatial transfer-matrices are constructed for 1D su(2)-spin and h4-bosonic many-body systems in external magnetic fields B(x) or potentials V(x). In the case of the spin system, generalized coherent states are applied to derive a path integral which can be reordered according to the spatial...

General stochastic dynamics, developed in a framework of Feynman path integrals, have been applied to Lewinian field-theoretic psychodynamics [K. Lewin, Field Theory in Social Science, University of Chicago Press, Chicago, 1951; K. Lewin, Resolving Social Conflicts, and, Field Theory in Social...

We derive a closed-form solution for the price of an average strike as well as an average price geometric Asian option, by making use of the path integral formulation. Our results are compared to a numerical Monte Carlo simulation. We also develop a pricing formula for an Asian option with a...

We define the Lagrangians in the momentum space and in mixed position-momentum spaces. In terms of the so-defined Lagrangians, the actions and the propagators are directly defined in the spaces, not as the Fourier transforms of their counterparts in the configuration space as previously known in...