264 research outputs found
Large-N CP(N-1) sigma model on a finite interval and the renormalized string energy
We continue the analysis started in a recent paper of the large-N
two-dimensional CP(N-1) sigma model, defined on a finite space interval L with
Dirichlet (or Neumann) boundary conditions. Here we focus our attention on the
problem of the renormalized energy density which is
found to be a sum of two terms, a constant term coming from the sum over modes,
and a term proportional to the mass gap. The approach to
at large is
shown, both analytically and numerically, to be exponential: no power
corrections are present and in particular no L\"uscher term appears. This is
consistent with the earlier result which states that the system has a unique
massive phase, which interpolates smoothly between the classical weakly-coupled
limit for and the "confined" phase of the standard CP(N-1)
model in two dimensions for .Comment: LaTeX: 32 pages, 11 figures; V2: appendices E and F added and typos
corrected; V3: grant information adde
Monopole-vortex complex in a theta vacuum
We discuss aspects of the monopole-vortex complex soliton arising in a
hierarchically broken gauge system, G to H to 1, in a theta vacuum of the
underlying G theory. Here we focus our attention mainly on the simplest such
system with G=SU(2) and H=U(1). A consistent picture of the effect of the theta
parameter is found both in a macroscopic, dual picture and in a microscopic
description of the monopole-vortex complex soliton.Comment: 18 pages 3 figure
Development of a magnetically suspended, tetrahedron-shaped antenna pointing system
A magnetically suspended, tetrahedron-shaped antenna pointing system is proposed for use in a multibeam broadcasting satellite system in the future. The structure of this system is presented, along with its design concept and the functional test results which were obtained in a laser tracking system in the laboratory. According to these results, it has been confirmed that the system has many advantages over conventional systems and excellent performance
Large- sigma model on a finite interval: general Dirichlet boundary conditions
This is the third of the series of articles on the large- two-dimensional
sigma model, defined on a finite space interval with
Dirichlet boundary conditions. Here the cases of the general Dirichlet boundary
conditions are studied, where the relative orientations at
the two boundaries are generic, and numerical solutions are presented.
Distinctive features of the sigma model, as compared e.g.,
to an model, which were not entirely evident in the basic properties
studied in the first two articles in the large limit, manifest themselves
here. It is found that the total energy is minimized when the fields are
aligned in the same direction at the two boundaries.Comment: Latex, 19 figure
- …