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Volodymyr Lyubashenko

Publications and source records attributed to Volodymyr Lyubashenko.

23 records · Page 2Linked to original sources

A-infinity-bimodules and Serre A-infinity-functors

We define A-infinity-bimodules similarly to Tradler and show that this notion is equivalent to an A-infinity-functor with two arguments which takes values in the differential graded category of complexes of k-modules, where k is a ground commutative ring. Serre A-infinity-functors are defined via A-infinity-bimodules likewise Kontsevich and Soibelman. We prove that a unital closed under shifts A-infinity-category A over a field k admits a Serre A-infinity-functor if and only if its homotopy category H^0(A) admits a Serre k-linear functor. The proof uses categories enriched in K, the homotopy category of complexes of k-modules, and Serre K-functors. Also we use a new A-infinity-version of the Yoneda Lemma generalizing the previously obtained result.

math.CT↗

External tensor product of categories of perverse sheaves

Under some assumptions we prove that the Deligne tensor product of categories of constructible perverse sheaves on pseudomanifolds X and Y is the category of constructible perverse sheaves on X\times Y. The Deligne external tensor product functor is identified with the geometrical external tensor product.

math.CT↗

The triangulated Hopf category n_+SL(2)

We discuss an example of a triangulated Hopf category related to SL(2). It is an equivariant derived category equipped with multiplication and comultiplication functors and structure isomorphisms. We prove some coherence equations for structure isomorphisms. In particular, the Hopf category is monoidal.

math.QA↗

Integrals for braided Hopf algebras

Let H be a Hopf algebra in a rigid braided monoidal category with split idempotents. We prove the existence of integrals on (in) H characterized by the universal property, employing results about Hopf modules, and show that their common target (source) object Int H is invertible. The fully braided version of Radford's formula for the fourth power of the antipode is obtained. Connections of integration with cross-product and transmutation are studied. The results apply to topological Hopf algebras, e.g. a torus with a hole, which do not have additive structure.

q-alg↗

Invariants of 3-manifolds and projective representations of mapping class groups via quantum groups at roots of unity

An example of a finite dimensional factorizable ribbon Hopf C-algebra is given by a quotient H=u_q(g) of the quantized universal enveloping algebra U_q(g) at a root of unity q of odd degree. The mapping class group M_{g,1} of a surface of genus g with one hole projectively acts by automorphisms in the H-module H^{*\otimes g}, if H^* is endowed with the coadjoint H-module structure. There exists a projective representation of the mapping class group M_{g,n} of a surface of genus g with n holes labelled by finite dimensional H-modules X_1,...,X_n in the vector space Hom_H(X_1\otimes...\otimes X_n,H^{*\otimes g}). An invariant of closed oriented 3-manifolds is constructed. Modifications of these constructions for a class of ribbon Hopf algebras satisfying weaker conditions than factorizability (including most of u_q(g) at roots of unity q of even degree) are described. The results are motivated by CFT.

hep-th↗