Peter Orland

Extrinsic curvature dependence of Nielsen-Olesen strings

Abstract It is shown how to treat the degrees of freedom of Nielsen-Olesen vortices in the 3 + 1-dimensional U(1) Higgs model by a collective coordinate method. In the London limit, where the Higgs mass becomes infinite, the gauge and goldstone degrees of freedom are integrated out, resulting in the vortex world-sheet action. Introducing an ultraviolet cut-off mimics the effect of finite Higgs mass. This action is non-polynomial in derivatives and depends on the extrinsic curvature of the surface. Flat surfaces are stable if the coherence length is less than the penetration depth. It is argued that in the quantum abelian Higgs model, vortex world-sheets are dominated by branched polymers.

String tensions and representations in anisotropic (2 + 1)-dimensional weakly-coupled Yang-Mills theory

In earlier papers we established quark confinement analytically in anisotropic

Summing planar diagrams by an integrable bootstrap. II

(2+1)

Integrable models and confinement in ( 2 + 1 ) -dimensional weakly-coupled Yang-Mills theory

-dimensional Yang-Mills theory with two gauge coupling constants. Here we point out a few features of the confining phase. These are: 1) the string tension in the

(2 + 1)-dimensional lattice QCD

x^{2}

Exact solution of a quantum gauge magnet in 2+1 dimensions

-direction as a function of representation obeys a sine law, and 2) static adjoint sources are not confined.

Longitudinal rescaling and high-energy effective actions

Correlation functions of matrix-valued fields are not generally known for massive renormalized field theories. We find the large-N limit of form factors of the (1+1)-dimensional sigma model with SU(N) X SU(N) symmetry. These form factors give a correction to the free-field approximation for the N=infinity Wightman function. The method is a combination of the 1/N-expansion of the S-matrix and Smirnovs form-factor axioms. We expand the renormalized field in terms of a free massive Bosonic field as N goes to infinity.

Extremal curves in (2+1)-dimensional Yang–Mills theory

We generalize the (2+1)-dimensional Yang-Mills theory to an anisotropic form with two gauge coupling constants

Seeing asymptotic freedom in an exact correlator of a large-Nmatrix field theory

e

Longitudinal rescaling of quantum electrodynamics

and