1,720,965 research outputs found
Non-linear integral equation and finite volume spectrum of minimal models perturbed by Phi((1,3))
Full text linkWe describe an extension of the non-linear integral equation (NLIE)
method to Virasoro minimal models perturbed by the relevant operator
Phi((1,3)). Along the way, we also complete our previous studies of the
finite volume spectrum of sine-Gordon theory by considering the
attractive regime and more specifically, breather states. For the
minimal models, we examine the states with zero topological charge in
detail, and give numerical comparison to TEA and TCS results. We think
that the evidence presented strongly supports the validity of the NLIE
description of perturbed minimal models, (C) 2000 Elsevier Science B.V.
All rights reserved
Infrared behaviour of massless integrable flows entering the minimal models from φ31
No full textIt is known that any minimal model Mp receives along its φ31 irrelevant direction two massless integrable flows: one from Mp+1 perturbed by φ13, the other from Zp-1 parafermionic model perturbed by its generating parafermion field. By comparing Thermodynamic Bethe Ansatz data and "predictions" of infrared Conformal Perturbation Theory we show that these two flows are received by Mp with opposite coupling constants of the φ31 irrelevant perturbation. Some comments on the massless S-matrices of these two flows are added
Lattice approach to excited TBA boundary flows: Tricritical Ising model
No full textWe show how a lattice approach can be used to derive Thermodynamic Bethe Ansatz (TBA) equations describing all excitations for boundary flows. The method is illustrated for a prototypical flow of the tricritical Ising model by considering the continuum scaling limit of the A4 lattice model with integrable boundaries. Fixing the bulk weights to their critical values, the integrable boundary weights admit two boundary fields ξ and η which play the role of the perturbing boundary fields φ1,3 and φ1,2 inducing the renormalization group flow between boundary fixed points. The excitations are completely classified in terms of (m,n) systems and quantum numbers but the string content changes by certain mechanisms along the flow. For our prototypical example, we identify these mechanisms and the induced map between the relevant finitized Virasoro characters. We also solve the boundary TBA equations numerically to determine the flows for the leading excitations. © 2002 Elsevier Science B.V. All rights reserved
Non-linear integral equation and finite volume spectrum of sine-Gordon theory
Full text linkWe examine the connection between the non-linear integral equation
(NLIE) derived from light-cone lattice and sine-Gordon quantum field
theory, considered as a perturbed c = 1 conformal field theory. After
clarifying some delicate points of the NLIE deduction from the lattice,
we compare both analytic and numerical predictions of the NLIE to
previously known results in sine-Gordon theory. To provide the basis
for the numerical comparison we use data from Truncated Conformal Space
method, Together with results from analysis of infrared and ultraviolet
asymptotics, we find evidence that it is necessary to change the rule
of quantization proposed by Destri and de Vega to a new one which
includes as a special case that of Fioravanti et al. This way we find
strong evidence for the validity of the NLIE as a description of the
finite size effects of sine-Gordon theory. (C) 1999 Elsevier Science
B.V
Exact phi_1,3 boundary flows in the tricritical Ising model
No full textWe consider the tricritical Ising model on a strip or cylinder under the integrable perturbation by the thermal 1,3 boundary field. This perturbation induces five distinct renormalization group (RG) flows between Cardy type boundary conditions labelled by the Kac labels (r,s). We study these boundary RG flows in detail for all excitations. Exact thermodynamic Bethe ansatz (TBA) equations are derived using the lattice approach by considering the continuum scaling limit of the A4 lattice model with integrable boundary conditions. Fixing the bulk weights to their critical values, the integrable boundary weights admit a thermodynamic boundary field ξ which induces the flow and, in the continuum scaling limit, plays the role of the perturbing boundary field 1,3. The excitations are completely classified, in terms of string content, by (m,n) systems and quantum numbers but the string content changes by either two or three well-defined mechanisms along the flow. We identify these mechanisms and obtain the induced maps between the relevant finitized Virasoro characters. We also solve the TBA equations numerically to determine the boundary flows for the leading excitations. © 2003 Elsevier B.V. All rights reserved
Truncated conformal space at c=1, nonlinear integral equation and quantization rules for multi-soliton states
Full text linkWe develop truncated conformal space (TCS) technique for perturbations
of c = 1 conformal field theories. We use it to give the first
numerical evidence of the validity of the non-linear integral equation
(NLIE) derived from light-cone lattice regularization at intermediate
scales. A controversy on the quantization of Bethe states is solved by
this numerical comparison and by using the locality principle at the
ultraviolet fu;ed point. It turns out that the correct quantization for
pure hole states is the one with half-integer quantum numbers
originally proposed by Fioravanti et al. [Phys. Lett. B 390 (1997)
243]. Once the correct rule is imposed, the agreement between TCS and
NLIE for pure hole states turns out to be impressive. (C) 1998 Elsevier
Science B.V. All rights reserved
Scaling functions in the odd charge sector of sine-Gordon/massive Thirring theory
Full text linkA non-linear integral equation (NLIE) governing the finite size effects
of excited states of even topological charge in the sine-Gordon (sG) /
massive Thirring (mTh) field theory, deducible from a light-cone
lattice formulation of the model, has been known for some time. In this
letter we conjecture an extension of this NLIE to states with odd
topological charge, thus completing the spectrum of the theory. The
scaling functions obtained as solutions to our conjectured NLIE are
compared successfully with Truncated Conformal Space data and the
construction is shown to be compatible with all other facts known about
the local Hilbert spaces of sG and mTh models. With the present results
we have achieved a full control over the finite size behaviour of
energy levels of sG/mTh theory. (C) 1998 Published by Elsevier Science
B.V. All rigths reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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