10,588 research outputs found
Description of D-branes invariant under the Poisson-Lie T-plurality
We write the conditions for open strings with charged endpoints in the
language of gluing matrices. We identify constraints imposed on the gluing
matrices that are essential in this setup and investigate the question of their
invariance under the Poisson-Lie T-plurality transformations. We show that the
chosen set of constraints is equivalent to the statement that the lifts of
D-branes into the Drinfel'd double are right cosets with respect to a maximally
isotropic subgroup and therefore it is invariant under the Poisson-Lie
T-plurality transformations.Comment: 22 pages; added references, the final version accepted for
publicatio
On the composition structure of the twisted Verma modules for
We discuss some aspects of the composition structure of twisted Verma modules
for the Lie algebra , including the explicit
structure of singular vectors for both and one
of its Lie subalgebras , and also of their
generators. Our analysis is based on the use of partial Fourier tranform
applied to the realization of twisted Verma modules as -modules
on the Schubert cells in the full flag manifold for
Robustly Solvable Constraint Satisfaction Problems
An algorithm for a constraint satisfaction problem is called robust if it
outputs an assignment satisfying at least -fraction of the
constraints given a -satisfiable instance, where
as . Guruswami and
Zhou conjectured a characterization of constraint languages for which the
corresponding constraint satisfaction problem admits an efficient robust
algorithm. This paper confirms their conjecture
Deciding absorption
We characterize absorption in finite idempotent algebras by means of
J\'onsson absorption and cube term blockers. As an application we show that it
is decidable whether a given subset is an absorbing subuniverse of an algebra
given by the tables of its basic operations
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