343 research outputs found
The BV-algebra structure of W_3 cohomology
We summarize some recent results obtained in collaboration with J. McCarthy
on the spectrum of physical states in gravity coupled to matter. We
show that the space of physical states, defined as a semi-infinite (or BRST)
cohomology of the algebra, carries the structure of a BV-algebra. This
BV-algebra has a quotient which is isomorphic to the BV-algebra of polyvector
fields on the base affine space of . Details have appeared elsewhere.
[Published in the proceedings of "Gursey Memorial Conference I: Strings and
Symmetries," Istanbul, June 1994, eds. G. Aktas et al., Lect. Notes in Phys.
447, (Springer Verlag, Berlin, 1995)]Comment: 8 pages; uses macros tables.tex and amssym.def (version 2.1 or later
Semi-infinite cohomology of W-algebras
We generalize some of the standard homological techniques to \cW-algebras,
and compute the semi-infinite cohomology of the \cW_3 algebra on a variety of
modules. These computations provide physical states in \cW_3 gravity coupled
to \cW_3 minimal models and to two free scalar fields.Comment: 15 page
Explicit Construction of Spin 4 Casimir Operator in the Coset Model
We generalize the Goddard-Kent-Olive (GKO) coset construction to the
dimension 5/2 operator for and compute the fourth order
Casimir invariant in the coset model with the generic unitary minimal
series that can be viewed as perturbations of the
limit, which has been investigated previously in the realization of
free fermion model.Comment: 11 page
Parametrised strict deformation quantization of C*-bundles and Hilbert C*-modules
In this paper, we use the parametrised strict deformation quantization of
C*-bundles obtained in a previous paper, and give more examples and
applications of this theory. In particular, it is used here to classify
H_3-twisted noncommutative torus bundles over a locally compact space. This is
extended to the case of general torus bundles and their parametrised strict
deformation quantization. Rieffel's basic construction of an algebra
deformation can be mimicked to deform a monoidal category, which deforms not
only algebras but also modules. As a special case, we consider the parametrised
strict deformation quantization of Hilbert C*-modules over C*-bundles with
fibrewise torus action.Comment: 13 page
Fock space resolutions of the Virasoro highest weight modules with c<=1
We extend Felder's construction of Fock space resolutions for the Virasoro
minimal models to all irreducible modules with . In particular, we
provide resolutions for the representations corresponding to the boundary and
exterior of the Kac table.Comment: 14 pages, revised versio
Twisted K-Theory from Monodromies
RR fluxes representing different cohomology classes may correspond to the
same twisted K-theory class. We argue that such fluxes are related by
monodromies, generalizing and sometimes T-dual to the familiar monodromies of a
D7-brane. A generalized theta angle is also transformed, but changes by a
multiple of 2pi. As an application, NS5-brane monodromies modify the twisted
K-theory classification of fluxes. Furthermore, in the noncompact case K-theory
does not distinguish flux configurations in which dG is nontrivial in compactly
supported cohomology. Such fluxes are realized as the decay products of
unstable D-branes that wrapped nontrivial cycles. This is interpreted using the
E8 bundle formalism.Comment: 24 Pages, 6 eps figure
T-Duality as a Duality of Loop Group Bundles
Representing the data of a string compactified on a circle in the background
of H-flux in terms of the geometric data of a principal loop group bundle, we
show that T-duality in type II string theory can be understood as the
interchange of the momentum and winding homomorphisms of the principal loop
group bundle, thus giving rise to a new interpretation of T-duality.Comment: 8 pages, latex 2e, new reference added, J.Phys.A: Fast Track
Publications (to appear
Rings of skew polynomials and Gel'fand-Kirillov conjecture for quantum groups
We introduce and study action of quantum groups on skew polynomial rings and
related rings of quotients. This leads to a ``q-deformation'' of the
Gel'fand-Kirillov conjecture which we partially prove. We propose a
construction of automorphisms of certain non-commutaive rings of quotients
coming from complex powers of quantum group generators; this is applied to
explicit calculation of singular vectors in Verma modules over
U_{q}(\gtsl_{n+1}).
We finally give a definition of a connection with coefficients in a ring
of skew polynomials and study the structure of quantum group modules twisted by
a connection.Comment: 25 page
A Note on the Equality of Algebraic and Geometric D-Brane Charges in WZW Models
The algebraic definition of charges for symmetry-preserving D-branes in
Wess-Zumino-Witten models is shown to coincide with the geometric definition,
for all simple Lie groups. The charge group for such branes is computed from
the ambiguities inherent in the geometric definition.Comment: 12 pages, fixed typos, added references and a couple of remark
Quasiparticle operators with non-Abelian braiding statistics
We study the gauge invariant fermions in the fermion coset representation of
Wess-Zumino-Witten models which create, by construction, the physical
excitations (quasiparticles) of the theory. We show that they provide an
explicit holomorphic factorization of Wess-Zumino-Witten primaries
and satisfy non-Abelian braiding relations.Comment: 13 pages, no figures, final version to appear in Physics Letters
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