We propose the Hamiltonian approach to the hydrodynamics of a compressible liquid with a free boundary based on perturbation theory and analytical continuation. Amplitudes of the bulk and surface waves play the role of canonical variables. We argue that there exist no local canonical variables....

The imaginary part of the dispersion laws of charged collective excitations in plasma (electron excitations in the usual plasma, and quark and gluon excitations in quark-gluon plasma) is discussed. It turns out to be anomalously large—much larger than the inverse free path time that determines...

A second order smectic A-smectic C phase transition in a 3D space has been analyzed by the renorm-group technique. The Frank moduli considered in the one-loop approximation have been shown to remain stable, which is valid for the region 7ln(103/τ)102 (τ is the dimensionless vicinity to the...