46 research outputs found
Effective Free Energy of Ginzburg-Landau Model
It is argued that the presence of a nonanalytic term in the effective
potential of the Ginzburg-Landau model is immaterial as far as the order of the
superconductor-normal phase transition is concerned. To achieve agreement with
the renormalization group, the effective potential has to be extended to
include derivative terms, which provide the theory with a low momentum scale
which can be varied to probe the (possible) fixed point.Comment: 6 pages, contribution to the Festschrift dedicated to Professor
Kleinert on the occasion of his 60th birthda
Effective Field Theory of ideal-fluid Hydrodynamics
Starting from a standard description of an ideal, isentropic fluid, we derive
the effective theory governing a gapless non-relativistic mode---the sound
mode. The theory, which is dictated by the requirement of Galilei invariance,
entails the entire set of hydrodynamic equations. The gaplessness of the sound
mode is explained by identifying it as the Goldstone mode associated with the
spontaneous breakdown of Galilei invariance. Differences with a superfluid are
pointed out.Comment: 17 pages, REVTe