The Feynman path integral approach for computing equilibrium isotope effects and isotope fractionation corrects the approximations made in standard methods, although at significantly increased computational cost. We describe an accelerated path integral ap ...
We develop a doubly spectral representation of a stationary functional time series, and study the properties of its empirical version. The representation decomposes the time series into an integral of uncorrelated frequency components (Cramer representatio ...
A functional integration approach – whose main ingredient is the Hubbard-Stratonovich transformation – for the quantum nonrelativistic many-fermion problem is investigated. With this method, the ground state energy correponds to a systematic expansion in p ...
A direct integration algorithm for the evaluation of Sommerfeld integrals is presented. This algorithm does not require the deformation of the integration path to avoid spectral singularities. The integration is performed along the real axis only. The algo ...
We investigate the ground state properties of large atoms and quantum dots described by a d-dimensional N-body Hamiltonian of confinement ZV. In atoms, d = 3 and V is the Coulomb interaction; in dots, d = 2 and V is phenomenologically determined. We expres ...
We present a study of atom-wall interactions in non-relativistic quantum electrodynamics by functional integral methods. The Feynman-Kac path integral representation is generalized when the particle interacts with a radiation field, providing an additional ...