1,390 research outputs found
On Extensions of Superconformal Algebras
Starting from vector fields that preserve a differential form on a Riemann
sphere with Grassmann variables, one can construct a Superconformal Algebra by
considering central extensions of the algebra of vector fields. In this note,
the N=4 case is analyzed closely, where the presence of weight zero operators
in the field theory forces the introduction of non-central extensions. How this
modifies the existing Field Theory, Representation Theory and Gelfand-Fuchs
constructions is discussed. It is also discussed how graded Riemann sphere
geometry can be used to give a geometrical description of the central charge in
the N=1 theory.Comment: 16 Pages, LaTeX2e, references added, typesetting fixed, Journal ref
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Boundary States, Extended Symmetry Algebra and Module Structure for certain Rational Torus Models
The massless bosonic field compactified on the circle of rational is
reexamined in the presense of boundaries. A particular class of models
corresponding to is distinguished by demanding the existence
of a consistent set of Newmann boundary states. The boundary states are
constructed explicitly for these models and the fusion rules are derived from
them. These are the ones prescribed by the Verlinde formula from the S-matrix
of the theory. In addition, the extended symmetry algebra of these theories is
constructed which is responsible for the rationality of these theories.
Finally, the chiral space of these models is shown to split into a direct sum
of irreducible modules of the extended symmetry algebra.Comment: 12 page
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