10,588 research outputs found

    Description of D-branes invariant under the Poisson-Lie T-plurality

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    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 sl(3,C)\mathfrak{sl}(3,\mathbb{C})

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    We discuss some aspects of the composition structure of twisted Verma modules for the Lie algebra sl(3,C)\mathfrak{sl}(3, \mathbb{C}), including the explicit structure of singular vectors for both sl(3,C)\mathfrak{sl}(3, \mathbb{C}) and one of its Lie subalgebras sl(2,C)\mathfrak{sl}(2, \mathbb{C}), 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 D\mathrm{{D}}-modules on the Schubert cells in the full flag manifold for SL(3,C)\mathrm{SL}(3, \mathbb{C})

    Robustly Solvable Constraint Satisfaction Problems

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    An algorithm for a constraint satisfaction problem is called robust if it outputs an assignment satisfying at least (1g(ε))(1-g(\varepsilon))-fraction of the constraints given a (1ε)(1-\varepsilon)-satisfiable instance, where g(ε)0g(\varepsilon) \rightarrow 0 as ε0\varepsilon \rightarrow 0. 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

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    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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