1,164 research outputs found
An Extension of the Character Ring of sl(3) and Its Quantisation
We construct a commutative ring with identity which extends the ring of
characters of finite dimensional representations of sl(3). It is generated by
characters with values in the group ring of the extended affine
Weyl group of at . The `quantised' version at
rational level realises the fusion rules of a WZW conformal field
theory based on admissible representations of .Comment: contains two TeX files: main file using harvmac.tex, amssym.def,
amssym.tex, 35p.; file with figures using XY-pic package, 4p; v2: minor
corrections, Note adde
Non-critical string pentagon equations and their solutions
We derive pentagon type relations for the 3-point boundary tachyon
correlation functions in the non-critical open string theory with generic
c_{matter} < 1 and study their solutions in the case of FZZ branes. A new
general formula for the Liouville 3-point factor is derived.Comment: 18 pages, harvmac; misprints corrected, section 3.2 extended, a new
general formula for the Liouville 3-point factor adde
Conformal Field Theories, Graphs and Quantum Algebras
This article reviews some recent progress in our understanding of the
structure of Rational Conformal Field Theories, based on ideas that originate
for a large part in the work of A. Ocneanu. The consistency conditions that
generalize modular invariance for a given RCFT in the presence of various types
of boundary conditions --open, twisted-- are encoded in a system of integer
multiplicities that form matrix representations of fusion-like algebras. These
multiplicities are also the combinatorial data that enable one to construct an
abstract ``quantum'' algebra, whose - and -symbols contain essential
information on the Operator Product Algebra of the RCFT and are part of a cell
system, subject to pentagonal identities. It looks quite plausible that the
classification of a wide class of RCFT amounts to a classification of ``Weak
- Hopf algebras''.Comment: 23 pages, 12 figures, LateX. To appear in MATHPHYS ODYSSEY 2001
--Integrable Models and Beyond, ed. M. Kashiwara and T. Miwa, Progress in
Math., Birkhauser. References and comments adde
On the crossing relation in the presence of defects
The OPE of local operators in the presence of defect lines is considered both
in the rational CFT and the Virasoro (Liouville) theory. The duality
transformation of the 4-point function with inserted defect operators is
explicitly computed. The two channels of the correlator reproduce the
expectation values of the Wilson and 't Hooft operators, recently discussed in
Liouville theory in relation to the AGT conjecture.Comment: TEX file with harvmac; v3: JHEP versio
Projected Heat-Related Mortality in the U.S. Urban Northeast
Increased heat-related mortality is projected to be among the major impacts of climate change on human health, and the United States urban Northeast region is likely to be particularly vulnerable. In support of regional adaptation planning, quantitative information is needed on potential future health responses at the urban and regional scales. Here, we present future projections of heat-related mortality in Boston, New York and Philadelphia utilizing downscaled next-generation climate models and Representative Concentration Pathways (RCPs) developed in support of the Intergovernmental Panel on Climate Change (IPCC)’s Fifth Assessment Report (AR5). Our analyses reveal that heat-related mortality rates per 100,000 of population during the baseline period between 1985 and 2006 were highest in Philadelphia followed by New York City and Boston. However, projected heat-related mortality rates in the 2020s, 2050s and 2080s were highest in New York City followed by Philadelphia and Boston. This study may be of value in developing strategies for reducing the future impacts of heat and building climate change resilience in the urban Northeast region
Dietary fat intake as a risk factor for the development of diabetes. Multinational, multicenter study of the Mediterranean Group for the Study of Diabetes (MGDS)
In the context of the Multinational MGSD Nutrition Study, three groups of subjects were studied: 204 subjects with recently diagnosed diabetes(RDM),42subjectswithundiagnoseddiabetes(UDM)(AmericanDiabetesAssociation criteria—fasting plasma glucose [FPG] 126 mg/dl), and 55 subjects with impaired fasting glucose(IFG)(FPG 110and126mg/dl).Eachgroupwascomparedwithacontrolgroupof nondiabetic subjects, matched one by one for center, sex, age, and BMI. Nutritional habits were evaluated by a dietary history method, validated against the 3-day diet diary. In RDM, the questionnaire referred to the nutritional habits before the diagnosis of diabetes. Demographic data were collected, and anthropometrical and biochemical measurements were taken. RESULTS— Compared with control subjects, RDM more frequently had a family history of diabetes(49.0vs.14.2%;P0.001),exercisedless(exerciseindex53.5vs.64.4;P0.01),and more frequently had sedentary professions (47.5 vs. 27.4%; P 0.001). Carbohydrates contributed less to their energy intake (53.5 vs. 55.1%; P 0.05), whereas total fat (30.2 0.5 vs. 27.8 0.5%; P 0.001) and animal fat (12.2 0.3 vs. 10.8 0.3%; P 0.01) contributed moreandtheplant-to-animalfatratiowaslower(1.50.1vs.1.80.1;P0.01).UDMmore frequentlyhadafamilyhistoryofdiabetes(38.1vs.19.0%;P0.05)andsedentaryprofessions (58.5vs.34.1%;P0.05),carbohydratescontributedlesstotheirenergyintake(47.61.7vs. 52.81.4%;P0.05),totalfat(34.71.5vs.30.41.2%;P0.05)andanimalfat(14.2 0.9 vs. 10.6 0.7%; P 0.05) contributed more, and the plant-to-animal fat ratio was lower (1.6 0.2 vs. 2.3 0.4; P 0.05). IFG differed only in the prevalence of family history of diabetes (32.7 vs. 16.4%; P 0.05). CONCLUSIONS— Our data support the view that increased animal fat intake is associated with the presence of diabetes
From conformal embeddings to quantum symmetries: an exceptional SU(4) example
We briefly discuss several algebraic tools that are used to describe the
quantum symmetries of Boundary Conformal Field Theories on a torus. The
starting point is a fusion category, together with an action on another
category described by a quantum graph. For known examples, the corresponding
modular invariant partition function, which is sometimes associated with a
conformal embedding, provides enough information to recover the whole
structure. We illustrate these notions with the example of the conformal
embedding of SU(4) at level 4 into Spin(15) at level 1, leading to the
exceptional quantum graph E4(SU(4)).Comment: 22 pages, 3 color figures. Version 2: We changed the color of figures
(ps files) in such a way that they are still understood when converted to
gray levels. Version 3: Several references have been adde
The Virtue of Defects in 4D Gauge Theories and 2D CFTs
We advance a correspondence between the topological defect operators in
Liouville and Toda conformal field theories - which we construct - and loop
operators and domain wall operators in four dimensional N=2 supersymmetric
gauge theories on S^4. Our computation of the correlation functions in
Liouville/Toda theory in the presence of topological defect operators, which
are supported on curves on the Riemann surface, yields the exact answer for the
partition function of four dimensional gauge theories in the presence of
various walls and loop operators; results which we can quantitatively
substantiate with an independent gauge theory analysis. As an interesting
outcome of this work for two dimensional conformal field theories, we prove
that topological defect operators and the Verlinde loop operators are different
descriptions of the same operators.Comment: 59 pages, latex; v2 corrections to some formula
Integrable Lattice Realizations of Conformal Twisted Boundary Conditions
We construct integrable realizations of conformal twisted boundary conditions
for ^sl(2) unitary minimal models on a torus. These conformal field theories
are realized as the continuum scaling limit of critical A-D-E lattice models
with positive spectral parameter. The integrable seam boundary conditions are
labelled by (r,s,\zeta) in (A_{g-2},A_{g-1},\Gamma) where \Gamma is the group
of automorphisms of G and g is the Coxeter number of G. Taking symmetries into
account, these are identified with conformal twisted boundary conditions of
Petkova and Zuber labelled by (a,b,\gamma) in (A_{g-2}xG, A_{g-2}xG,Z_2) and
associated with nodes of the minimal analog of the Ocneanu quantum graph. Our
results are illustrated using the Ising (A_2,A_3) and 3-state Potts (A_4,D_4)
models.Comment: 11 pages, LaTeX. Added some reference
't Hooft Operators in Gauge Theory from Toda CFT
We construct loop operators in two dimensional Toda CFT and calculate with
them the exact expectation value of certain supersymmetric 't Hooft and dyonic
loop operators in four dimensional \Ncal=2 gauge theories with SU(N) gauge
group. Explicit formulae for 't Hooft and dyonic operators in \Ncal=2^* and
\Ncal=2 conformal SQCD with SU(N) gauge group are presented. We also briefly
speculate on the Toda CFT realization of arbitrary loop operators in these
gauge theories in terms of topological web operators in Toda CFT.Comment: 49 pages, LaTeX. Typos fixed, references adde
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