21,744 research outputs found
Least-action principle and path-integral for classical mechanics
In this paper we show how the equations of motion of a superfield, which
makes its appearance in a path-integral approach to classical mechanics, can be
derived without the need of the least-action principleComment: to appear IN PHYS.REV.D (Brief Report
Metallic Continuum Quantum Ferromagnets at Finite Temperature
We study via renormalization group (RG) and large N methods the problem of
continuum SU(N) quantum Heisenberg ferromagnets (QHF) coupled to gapless
electrons. We establish the phase diagram of the dissipative problem and
investigate the changes in the Curie temperature, magnetization, and magnetic
correlation length due to dissipation and both thermal and quantum
fluctuations. We show that the interplay between the topological term (Berry's
phase) and dissipation leads to non-trivial effects for the finite temperature
critical behavior.Comment: Corrected typos, new discussion of T=0 results, to appear in
Europhys. Let
Wave polarizations for a beam-like gravitational wave in quadratic curvature gravity
We compute analytically the tidal field and polarizations of an exact
gravitational wave generated by a cylindrical beam of null matter of finite
width and length in quadratic curvature gravity. We propose that this wave can
represent the gravitational wave that keep up with the high energy photons
produced in a gamma ray burst (GRB) source.Comment: 5 pages, 3 figures, minor corrections, to appear in CQ
Mass formula for T=0 and T=1 ground states of N=Z nuclei
An algebraic model is developed to calculate the T=0 and T=1 ground state
binding energies for N=Z nuclei. The method is tested in the sd shell and is
then extended to 28-50 shell which is currently the object of many experimental
studies.Comment: 5 figure
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