186 research outputs found
Quantum spin chains of Temperley-Lieb type: periodic boundary conditions, spectral multiplicities and finite temperature
We determine the spectra of a class of quantum spin chains of Temperley-Lieb
type by utilizing the concept of Temperley-Lieb equivalence with the S=1/2 XXZ
chain as a reference system. We consider open boundary conditions and in
particular periodic boundary conditions. For both types of boundaries the
identification with XXZ spectra is performed within isomorphic representations
of the underlying Temperley-Lieb algebra. For open boundaries the spectra of
these models differ from the spectrum of the associated XXZ chain only in the
multiplicities of the eigenvalues. The periodic case is rather different. Here
we show how the spectrum is obtained sector-wise from the spectra of globally
twisted XXZ chains. As a spin-off, we obtain a compact formula for the
degeneracy of the momentum operator eigenvalues. Our representation theoretical
results allow for the study of the thermodynamics by establishing a
TL-equivalence at finite temperature and finite field.Comment: 29 pages, LaTeX, two references added, redundant figures remove
On the Temperley-Lieb reflection matrices
This work concerns the boundary integrability of the spin-s
Temperley-Lieb model. A systematic computation method is
used to constructed the solutions of the boundary Yang-Baxter equations. For
half-integer, a general free parameter solution is presented.
It turns that for integer, the general solution has free
parameters. Moreover, some particular solutions are discussed.Comment: LaTex 17 page
Bifurcations, order, and chaos in the Bose-Einstein condensation of dipolar gases
We apply a variational technique to solve the time-dependent Gross-Pitaevskii
equation for Bose-Einstein condensates in which an additional dipole-dipole
interaction between the atoms is present with the goal of modelling the
dynamics of such condensates. We show that universal stability thresholds for
the collapse of the condensates correspond to bifurcation points where always
two stationary solutions of the Gross-Pitaevskii equation disappear in a
tangent bifurcation, one dynamically stable and the other unstable. We point
out that the thresholds also correspond to "exceptional points," i.e. branching
singularities of the Hamiltonian. We analyse the dynamics of excited condensate
wave functions via Poincare surfaces of section for the condensate parameters
and find both regular and chaotic motion, corresponding to (quasi-)
periodically oscillating and irregularly fluctuating condensates, respectively.
Stable islands are found to persist up to energies well above the saddle point
of the mean-field energy, alongside with collapsing modes. The results are
applicable when the shape of the condensate is axisymmetric.Comment: 10 pages, 4 figures, minor changes in the text and additional
reference adde
Scaling limit of the one-dimensional attractive Hubbard model: The half-filled band case
The scaling limit of the higher level Bethe Ansatz (HLBA) equations for a
macroscopically half-filled Hubbard chain is considered. These equations
practically decouple into three disjoint sets which are again of the BA type,
and correspond to the secular equations of three different kinds of dressed
particles (one massive and two massless). The finite size corrections and the
fine structure of the spectrum show that the massless sector corresponds to a
conformal field with central charge c=1 and Gaussian anomalous dimensions. The
zero temperature free energy is also calculated and is found to be in perfect
agreement with the results of a perturbative calculation in the SU(2) chiral
Gross-Neveu (CGN) model.Comment: LATEX, uses Revtex, 39 page
Scattering and Thermodynamics of Integrable N=2 Theories
We study =2 supersymmetric integrable theories with spontaneously-broken
\Zn\ symmetry. They have exact soliton masses given by the affine Toda
masses and fractional fermion numbers given by multiples of . The basic
such =2 integrable theory is the -type =2 minimal model perturbed by
the most relevant operator. The soliton content and exact S-matrices are
obtained using the Landau-Ginzburg description. We study the thermodynamics of
these theories and calculate the ground-state energies exactly, verifying that
they have the correct conformal limits. We conjecture that the soliton content
and S-matrices in other integrable \Zn\ =2 theories are given by the tensor
product of the above basic =2 \Zn\ scattering theory with various =0
theories. In particular, we consider integrable perturbations of =2
Kazama-Suzuki models described by generalized Chebyshev potentials,
sigma models, and =2 sine-Gordon and its affine Toda generalizations.Comment: 31 page
Statistical Models with a Line of Defect
The factorization condition for the scattering amplitudes of an integrable
model with a line of defect gives rise to a set of Reflection-Transmission
equations. The solutions of these equations in the case of diagonal -matrix
in the bulk are only those with . The choice corresponds to
the Ising model. We compute the transmission and reflection amplitudes relative
to the interaction of the Majorana fermion with the defect and we discuss their
relevant features.Comment: 14 pages, LATEX file, ISAS/EP/94/30 (Figures added, originally missed
for E-mail transmission problem.
Fungal Chitin Dampens Inflammation through IL-10 Induction Mediated by NOD2 and TLR9 Activation
Funding: JW and NARG thank the Wellcome Trust (080088, 086827, 075470), The Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377) and the European Union ALLFUN (FP7/2007 2013, HEALTH-2010-260338) for funding. MGN was supported by a Vici grant of the Netherlands Organisation for Scientific Research. AJPB and DMM were funded by STRIFE, ERC-2009-AdG-249793 and AJPB additionally by FINSysB, PITN-GA-2008-214004 and the BBSRC [BB/F00513X/1]. MDL was supported by the MRC (MR/J008230/1). GDB and SV were funded by the Wellcome Trust (086558) and TB and MK were funded by the Deutsche Forschungsgemeinschaft (Bi 696/3-1; Bi 696/5-2; Bi 696/10-1). MS was supported by the Deutsche Forschungsgemeinschaft (Sch 897/1-3) and the National Institute of Dental and Craniofacial Research (R01 DE017514-01). TDK and RKSM were funded by the National Institute of Health (AR056296, AI101935) and the American Lebanese Syrian Associated Charities (ALSAC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Correlation Functions in 2-Dimensional Integrable Quantum Field Theories
In this talk I discuss the form factor approach used to compute correlation
functions of integrable models in two dimensions. The Sinh-Gordon model is our
basic example. Using Watson's and the recursive equations satisfied by matrix
elements of local operators, I present the computation of the form factors of
the elementary field and the stress-energy tensor of
the theory.Comment: 19pp, LATEX version, (talk at Como Conference on ``Integrable Quantum
Field Theories''
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