115 research outputs found
Conformal Partial Waves and the Operator Product Expansion
By solving the two variable differential equations which arise from finding
the eigenfunctions for the Casimir operator for succinct expressions
are found for the functions, conformal partial waves, representing the
contribution of an operator of arbitrary scale dimension and spin
together with its descendants to conformal four point functions for
, recovering old results, and also for . The results are expressed in
terms of ordinary hypergeometric functions of variables which are simply
related to the usual conformal invariants. An expression for the conformal
partial wave amplitude valid for any dimension is also found in terms of a sum
over two variable symmetric Jack polynomials which is used to derive relations
for the conformal partial waves.Comment: 17 pages, uses harvmac, v2 correction to eq. 2.2
Conjectures for Large N Superconformal N=4 Chiral Primary Four Point Functions
An expression for the four point function for half-BPS operators belonging to
the [0,p,0] SU(4) representation in N=4 superconformal theories at strong
coupling in the large N limit is suggested for any p. It is expressed in terms
of the four point integrals defined by integration over AdS_5 and agrees with,
and was motivated by, results for p=2,3,4 obtained via the AdS/CFT
correspondence. Using crossing symmetry and unitarity, the detailed form is
dictated by the requirement that at large N the contribution of long multiplets
with twist less than 2p, which do not have anomalous dimensions, should cancel
corresponding free field contributions.Comment: 50 pages, 1 figure, uses harvmac, version 2 extra reference, minor
change
Conformal Partial Wave Expansions for N=4 Chiral Four Point Functions
The conformal partial wave analysis of four point functions of half BPS
operators belonging to the SU(4) [0,p,0] representation is undertaken for
p=2,3,4. Using the results of N=4 superconformal Ward identities the
contributions from protected short and semi-short multiplets are identified in
terms of the free field theory. In the large N limit contributions
corresponding to long multiplets with twist up to 2p-2 are absent. The
anomalous dimensions for twist two singlet multiplets are found to order g^4
and agree with other perturbative calculations. Results for twist four and six
are also found.Comment: 53 pages, uses harvmac, includes 1 figure, version 2 some corrections
and minor extensions, version 3 some further corrections, version 4 as to be
publishe
Noncommutative vector bundles over fuzzy CP^N and their covariant derivatives
We generalise the construction of fuzzy CP^N in a manner that allows us to
access all noncommutative equivariant complex vector bundles over this space.
We give a simplified construction of polarization tensors on S^2 that
generalizes to complex projective space, identify Laplacians and natural
noncommutative covariant derivative operators that map between the modules that
describe noncommuative sections. In the process we find a natural
generalization of the Schwinger-Jordan construction to su(n) and identify
composite oscillators that obey a Heisenberg algebra on an appropriate Fock
space.Comment: 34 pages, v2 contains minor corrections to the published versio
Superconformal Symmetry, Correlation Functions and the Operator Product Expansion
Superconformal transformations are derived for the \N=4\N=2$ or 4
superconformal identities are derived for the functions of the two conformal
invariants appearing in the four point function for the chiral primary
operator. These are solved in terms of a single arbitrary function of the two
conformal invariants and one or three single variable functions. The results
are applied to the operator product expansion using the exact formula for the
contribution of an operator in the operator product expansion in four
dimensions to a scalar four point function. Explicit expressions representing
exactly the contribution of both long and possible short supermultiplets to the
chiral primary four point function are obtained. These are applied to give the
leading perturbative and large N corrections to the scale dimensions of long
supermultiplets.Comment: 75 pages, plain TeX file using harvmac; revised version, minor
corrections and extra referenc
Superconformal Indices for Orbifold Chern-Simons Theories
We calculate the superconformal indices of recently discovered
three-dimensional N=4,5 Chern-Simons-matter theories and compare them with the
corresponding indices of supergravity on AdS4 times orbifolds of S7. We find
perfect agreement in the large N and large k limit, provided that the twisted
sector contributions at the fixed loci of the orbifolds are properly taken into
account. We also discuss the index for the so-called "dual ABJM" proposal.Comment: 27 pages, 1 figure; v2. reference added, minor correction
Conformal Four Point Functions and the Operator Product Expansion
Various aspects of the four point function for scalar fields in conformally
invariant theories are analysed. This depends on an arbitrary function of two
conformal invariants u,v. A recurrence relation for the function corresponding
to the contribution of an arbitrary spin field in the operator product
expansion to the four point function is derived. This is solved explicitly in
two and four dimensions in terms of ordinary hypergeometric functions of
variables z,x which are simply related to u,v. The operator product expansion
analysis is applied to the explicit expressions for the four point function
found for free scalar, fermion and vector field theories in four dimensions.
The results for four point functions obtained by using the AdS/CFT
correspondence are also analysed in terms of functions related to those
appearing in the operator product discussion.Comment: 38 pages, plain TeX file using harvmac; revised version minor changes
and an extra reference, revised version2, further correction
New methods in conformal partial wave analysis
We report on progress concerning the partial wave analysis of higher
correlation functions in conformal quantum field theory.Comment: 16 page
Applications of the Superconformal Index for Protected Operators and q-Hypergeometric Identities to N=1 Dual Theories
The results of Romelsberger for a N=1 superconformal index counting protected
operators, satisfying a BPS condition and which cannot be combined to form long
multiplets, are analysed further. The index is expressible in terms of single
particle superconformal characters for N=1 scalar and vector multiplets. For
SQCD, involving SU(N_c) gauge groups and appropriate numbers of flavours N_f,
the formula used to construct the index may be proved to give identical results
for theories linked by Seiberg duality using recently proved theorems for
q-series elliptic hypergeometric integrals. The discussion is also extended to
Kutasov-Schwimmer dual theories in the large N_c, N_f limit and to dual
theories with Sp(N) and SO(N) gauge groups. For the former, a transformation
identity for elliptic hypergeometric integrals directly verifies that the index
is the same for the electric and magnetic theories. For SO(N) theories the
corresponding result may also be obtained from the same basic identity. An
expansion of the index to several orders is also obtained in a form where the
detailed protected operator content may be read off. Relevant mathematical
results are reviewed.Comment: 47 pages, uses harvmac, v2. minor corrections, SO(N) cases proved,
ref. added, v3. minor additions and correction
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