519 research outputs found
Boundary reduction formula
An asymptotic theory is developed for general non-integrable boundary quantum
field theory in 1+1 dimensions based on the Langrangean description. Reflection
matrices are defined to connect asymptotic states and are shown to be related
to the Green functions via the boundary reduction formula derived. The
definition of the -matrix for integrable theories due to Ghoshal and
Zamolodchikov and the one used in the perturbative approaches are shown to be
related.Comment: 12 pages, Latex2e file with 5 eps figures, two Appendices about the
boundary Feynman rules and the structure of the two point functions are adde
A2 Toda theory in reduced WZNW framework and the representations of the W algebra
Using the reduced WZNW formulation we analyse the classical orbit content
of the space of classical solutions of the Toda theory. We define the
quantized Toda field as a periodic primary field of the algebra satisfying
the quantized equations of motion. We show that this local operator can be
constructed consistently only in a Hilbert space consisting of the
representations corresponding to the minimal models of the algebra.Comment: 38 page
Finite volume form factors in the presence of integrable defects
We developed the theory of finite volume form factors in the presence of
integrable defects. These finite volume form factors are expressed in terms of
the infinite volume form factors and the finite volume density of states and
incorporate all polynomial corrections in the inverse of the volume. We tested
our results, in the defect Lee-Yang model, against numerical data obtained by
truncated conformal space approach (TCSA), which we improved by renormalization
group methods adopted to the defect case. To perform these checks we determined
the infinite volume defect form factors in the Lee-Yang model exactly,
including their vacuum expectation values. We used these data to calculate the
two point functions, which we compared, at short distance, to defect CFT. We
also derived explicit expressions for the exact finite volume one point
functions, which we checked numerically. In all of these comparisons excellent
agreement was found.Comment: pdflatex, 34 pages, many figure
SUSY sine-Gordon theory as a perturbed conformal field theory and finite size effects
We consider SUSY sine-Gordon theory in the framework of perturbed conformal field theory. Using an argument from Zamolodchikov, we obtain the vacuum structure and the kink adjacency diagram of the theory, which is cross-checked against the exact S-matrix prediction, first-order perturbed conformal field theory (PCFT), the NLIE method and truncated conformal space approach. We provide evidence for consistency between the usual Lagrangian description and PCFT on the one hand, and between PCFT, NLIE and a massgap formula conjectured by Baseilhac and Fateev, on the other. In addition, we extend the NLIE description to all the vacua of the theory. (C) 2003 Elsevier B.V. All rights reserved
Boundary sine-Gordon model
We review our recent results on the on-shell description of sine-Gordon model
with integrable boundary conditions. We determined the spectrum of boundary
states together with their reflection factors by closing the boundary bootstrap
and checked these results against WKB quantization and numerical finite volume
spectra obtained from the truncated conformal space approach. The relation
between a boundary resonance state and the semiclassical instability of a
static classical solution is analyzed in detail.Comment: 15 pages, 7 eps figures, Talk presented at 'Workshop on Integrable
Theories, Solitons and Duality', 1-6 July 2002, Sao Paulo, Brazi
Finite size effects in boundary sine-Gordon theory
We examine the finite volume spectrum and boundary energy in boundary
sine-Gordon theory, based on our recent results obtained by closing the
boundary bootstrap. The spectrum and the reflection factors are checked
against truncated conformal space, together with a (still unpublished)
prediction by Al.B. Zamolodchikov for the boundary energy and the
relation between the parameters of the scattering amplitudes and of the
perturbed CFT Hamiltonian. In addition, a derivation of Zamolodchikov's
formulae is given. We find an entirely consistent picture and strong
evidence for the validity of the conjectured spectrum and scattering
amplitudes, which together give a complete description of the boundary
sine-Gordon theory on mass shell. (C) 2002 Elsevier Science B.V. All
rights reserved
Exact Maximal Height Distribution of Fluctuating Interfaces
We present an exact solution for the distribution P(h_m,L) of the maximal
height h_m (measured with respect to the average spatial height) in the steady
state of a fluctuating Edwards-Wilkinson interface in a one dimensional system
of size L with both periodic and free boundary conditions. For the periodic
case, we show that P(h_m,L)=L^{-1/2}f(h_m L^{-1/2}) for all L where the
function f(x) is the Airy distribution function that describes the probability
density of the area under a Brownian excursion over a unit interval. For the
free boundary case, the same scaling holds but the scaling function is
different from that of the periodic case. Numerical simulations are in
excellent agreement with our analytical results. Our results provide an exactly
solvable case for the distribution of extremum of a set of strongly correlated
random variables.Comment: 4 pages revtex (two-column), 1 .eps figure include
Finite volume form factors in the presence of integrable defects
We developed the theory of finite volume form factors in the presence of integrable defects. These finite volume form factors are expressed in terms of the infinite volume form factors and the finite volume density of states and incorporate all polynomial corrections in the inverse of the volume. We tested our results, in the defect Lee-Yang model, against numerical data obtained by truncated conformal space approach (TCSA), which we improved by renormalization group methods adopted to the defect case. To perform these checks we determined the infinite volume defect form factors in the Lee-Yang model exactly, including their vacuum expectation values. We used these data to calculate the two point functions, which we compared, at short distance, to defect CFT. We also derived explicit expressions for the exact finite volume one point functions, which we checked numerically. In all of these comparisons excellent agreement was found. © 2014 The Authors
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