44 research outputs found
off-shell Bethe ansatz equation with boundary terms
This work is concerned with the quasi-classical limit of the boundary quantum
inverse scattering method for the vertex model with diagonal
-matrices. In this limit Gaudin's Hamiltonians with boundary terms are
presented and diagonalized. Moreover, integral representations for correlation
functions are realized to be solutions of the trigonometric
Knizhnik-Zamoldchikov equations.Comment: 38 pages, minor revison, LaTe
Exact Results for Supersymmetric Sigma Models
We show that the metric and Berry's curvature for the ground states of
supersymmetric sigma models can be computed exactly as one varies the Kahler
structure. For the case of these are related to special solutions of
affine toda equations. This allows us to extract exact results (including exact
instanton corrections). We find that the ground state metric is non-singular as
the size of the manifold shrinks to zero thus suggesting that 2d QFT makes
sense even beyond zero radius. In other words it seems that manifolds with zero
size are non-singular as target spaces for string theory (even when they are
not conformal). The cases of and are discussed in more detail.Comment: 9
The algebraic Bethe ansatz for open vertex models
We present a unified algebraic Bethe ansatz for open vertex models which are
associated with the non-exceptional
Lie algebras.
By the method, we solve these models with the trivial K matrix and find that
our results agree with that obtained by analytical
Bethe ansatz. We also solve the models with
some non-trivial diagonal K-matrices (one free parameter case) by the algebraic
Bethe ansatz.Comment: Latex, 35 pages, new content and references are added, minor
revisions are mad
Gaudin model and its associated Knizhnik-Zamolodchikov equation
The semiclassical limit of the algebraic Bethe Ansatz for the Izergin-Korepin
19-vertex model is used to solve the theory of Gaudin models associated with
the twisted R-matrix. We find the spectra and eigenvectors of the
independents Gaudin Hamiltonians. We also use the off-shell Bethe Ansatz
method to show how the off-shell Gaudin equation solves the associated
trigonometric system of Knizhnik-Zamolodchikov equations.Comment: 20 pages,no figure, typos corrected, LaTe
Renormalization group trajectories from resonance factorized S-matrices
We propose and investigate a large class of models possessing resonance
factorized S-matrices. The associated Casimir energy describes a rich pattern
of renormalization group trajectories related to flows in the coset models
based on the simply laced Lie Algebras. From a simplest resonance S-matrix,
satisfying the ``-property'', we predict new flows in non-unitary
minimal models.Comment: (7 pages) (no figures included
Jorge A. Swieca's contributions to quantum field theory in the 60s and 70s and their relevance in present research
After revisiting some high points of particle physics and QFT of the two
decades from 1960 to 1980, I comment on the work by Jorge Andre Swieca. I
explain how it fits into the quantum field theory during these two decades and
draw attention to its relevance to the ongoing particle physics research. A
particular aim of this article is to direct thr readers mindfulness to the
relevance of what at the time of Swieca was called "the Schwinger Higgs
screening mechanism". which, together with recent ideas which generalize the
concept of gauge theories, has all the ingredients to revolutionize the issue
of gauge theories and the standard model.Comment: 49 pages, expansion and actualization of text, improvement of
formulations and addition of many references to be published in EPJH -
Historical Perspectives on Contemporary Physic