189 research outputs found
Logarithmic Operators and Dynamical Extention of The Symmetry Group in the Bosonic SU(2)_0 and SUSY SU(2)_2 WZNW Models
We study the operator product expansion in the bosonic and SUSY
WZNW models. We find that these OPEs contain both logarithmic
operators and new conserved currents, leading to an extension of the symmetry
group.Comment: 16 pages, Late
Density of states of the interacting two-dimensional electron gas
We study the influence of electron-electron interactions on the density of
states (DOS) of clean 2D electron gas. We confirm the linear cusp in the DOS
around the Fermi level, which was obtained previously. The cusp crosses over to
a pure logarithmic dependence further away from the Fermi surface.Comment: RevTeX, 3 pages, no figure
Global Conformal Invariance in D-dimensions and Logarithmic Correlation Functions
We define transformation of multiplets of fields (Jordan cells) under the
D-dimensional conformal group, and calculate two and three point functions of
fields, which show logarithmic behaviour. We also show how by a formal
differentiation procedure, one can obtain n-point function of logarithmic field
theory from those of ordinary conformal field theory.Comment: 9 pages, LaTeX, some misprints are corrected, to be published in
Phys. Lett.
Logarithmic Conformal Field Theories via Logarithmic Deformations
We construct logarithmic conformal field theories starting from an ordinary
conformal field theory -- with a chiral algebra C and the corresponding space
of states V -- via a two-step construction: i) deforming the chiral algebra
representation on V\tensor End K[[z,1/z]], where K is an auxiliary
finite-dimensional vector space, and ii) extending C by operators corresponding
to the endomorphisms End K. For K=C^2, with End K being the two-dimensional
Clifford algebra, our construction results in extending C by an operator that
can be thought of as \partial^{-1}E, where \oint E is a fermionic screening.
This covers the (2,p) Virasoro minimal models as well as the sl(2) WZW theory.Comment: LaTeX, 35 pages, 4 eps figures. v2: references adde
Critical Temperature of the Deconfining Phase Transition in (2+1)d Georgi-Glashow Model
We find the temperature of the phase transition in the (2+1)d Georgi-Glashow
model. The critical temperature is shown to depend on the gauge coupling and on
the ratio of Higgs and gauge boson masses. In the BPS limit of light Higgs the
previous result by Dunne, Kogan, Kovner, and Tekin is reproduced.Comment: 17 pages, 3 figures, REVTeX
Disordered Dirac Fermions: Multifractality Termination and Logarithmic Conformal Field Theories
We reexamine in detail the problem of fermions interacting with a non-Abelian
random vector potential. Without resorting to the replica or supersymmetry
approaches, we show that in the limit of infinite disorder strength the theory
possesses an exact solution which takes the form of a logarithmic conformal
field theory. We show that the proper treatment of the locality conditions in
the SU(2) theory leads to the termination of the multifractal spectrum, or in
other words to the termination of the infinite hierarchies of
negative-dimensional operators that were thought to occur. Based on arguments
of logarithmic degeneracies, we conjecture that such a termination mechanism
should be present for general SU(N). Moreover, our results lead to the
conclusion that the previous replica solution of this problem yields incorrect
results.Comment: Revised version, to appear in Nucl. Phys.
Logarithmic extensions of minimal models: characters and modular transformations
We study logarithmic conformal field models that extend the (p,q) Virasoro
minimal models. For coprime positive integers and , the model is defined
as the kernel of the two minimal-model screening operators. We identify the
field content, construct the W-algebra W(p,q) that is the model symmetry (the
maximal local algebra in the kernel), describe its irreducible modules, and
find their characters. We then derive the SL(2,Z) representation on the space
of torus amplitudes and study its properties. From the action of the
screenings, we also identify the quantum group that is Kazhdan--Lusztig-dual to
the logarithmic model.Comment: 43pp., AMSLaTeX++. V3: Some explanatory comments added, notational
inaccuracies corrected, references adde
Elasticity-driven interaction between vortices in type-II superconductors
The contribution to the vortex lattice energy which is due to the
vortex-induced strains is calculated covering all the magnetic field range
which defines the vortex state. This contribution is compared with previously
reported ones what shows that, in the most part of the vortex state, it has
been notably underestimated until now. The reason of such underestimation is
the assumption that only the vortex cores induce strains. In contrast to what
is generally assumed, both core and non-core regions are important sources of
strains in high- superconductors.Comment: 10 pages, 1 figure, revtex
Extended chiral algebras in the SU(2)_0 WZNW model
We investigate the W-algebras generated by the integer dimension chiral
primary operators of the SU(2)_0 WZNW model. These have a form almost identical
to that found in the c=-2 model but have, in addition, an extended Kac-Moody
structure. Moreover on Hamiltonian reduction these SU(2)_0 W-algebras exactly
reduce to those found in c=-2. We explicitly find the free field
representations for the chiral j=2 and j=3 operators which have respectively a
fermionic doublet and bosonic triplet nature. The correlation functions of
these operators accounts for the rational solutions of the
Knizhnik-Zamolodchikov equation that we find. We explicitly compute the full
algebra of the j=2 operators and find that the associativity of the algebra is
only guaranteed if certain null vectors decouple from the theory. We conjecture
that these algebras may produce a quasi-rational conformal field theory.Comment: 18 pages LATEX. Minor corrections. Full j=2 algebra adde
Extended multiplet structure in Logarithmic Conformal Field Theories
We use the process of quantum hamiltonian reduction of SU(2)_k, at rational
level k, to study explicitly the correlators of the h_{1,s} fields in the
c_{p,q} models. We find from direct calculation of the correlators that we have
the possibility of extra, chiral and non-chiral, multiplet structure in the
h_{1,s} operators beyond the `minimal' sector. At the level of the vacuum null
vector h_{1,2p-1}=(p-1)(q-1) we find that there can be two extra non-chiral
fermionic fields. The extra indicial structure present here permeates
throughout the entire theory. In particular we find we have a chiral triplet of
fields at h_{1,4p-1}=(2p-1)(2q-1). We conjecture that this triplet algebra may
produce a rational extended c_{p,q} model. We also find a doublet of fields at
h_{1,3p-1}=(\f{3p}{2}-1)(\f{3q}{2}-1). These are chiral fermionic operators if
p and q are not both odd and otherwise parafermionic.Comment: 24 pages LATEX. Minor corrections and extra reference
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