13 research outputs found
Heat kernel expansion: user's manual
The heat kernel expansion is a very convenient tool for studying one-loop
divergences, anomalies and various asymptotics of the effective action. The aim
of this report is to collect useful information on the heat kernel coefficients
scattered in mathematical and physical literature. We present explicit
expressions for these coefficients on manifolds with and without boundaries,
subject to local and non-local boundary conditions, in the presence of various
types of singularities (e.g., domain walls). In each case the heat kernel
coefficients are given in terms of several geometric invariants. These
invariants are derived for scalar and spinor theories with various
interactions, Yang-Mills fields, gravity, and open bosonic strings. We discuss
the relations between the heat kernel coefficients and quantum anomalies,
corresponding anomalous actions, and covariant perturbation expansions of the
effective action (both "low-" and "high-energy" ones).Comment: 113 pp, to be submitted to Phys.Repts, v2: added references and
corrected typo
Conformational study of ribonucleotides, 2?-deoxyribonucleotides, and arabinonucleotides by carbon-13 nuclear magnetic resonance
Interference of a Bose-Einstein condensate in a hard-wall trap: from nonlinear Talbot effect to formation of vorticity
We theoretically study the coherent expansion of a Bose-Einstein condensate in the presence of a confining impenetrable hard-wall potential. The nonlinear dynamics of the macroscopically coherent matter field results in rich and complex spatio-temporal self-interference patterns demonstrating a nonlinear Talbot effect, and the formation of vorticity and solitonlike structures