Lista referatów

• 2022-11-02, godz. 17:15, 405 IMPAN & ZOOM

  SØREN EILERS (Københavns Universitet)

  EQUIVARIANT ISOMORPHISMS OF QUANTUM LENS SPACES

  Since their inception two decades ago, the quantum lens spaces of Hong and Szymański have been studied very successfully, due in no small part to the fact — established from the outset — that they are graph C*-algebras. Every quantum lens space comes with a natural circle action, leadin...

• 2022-10-26, godz. 17:15, ZOOM

  PIOTR M. HAJAC (IMPAN)

  COUNTING PATHS IN DIRECTED GRAPHS

  We consider the class of directed graphs with N edges and without loops shorter than k. Using the concept of a labelled graph and a recent result of Alexandru Chirvasitu, I will show how to determine graphs from this class (they can be viewed as graphs labelled by the semiring of n...

• 2022-10-19, godz. 17:15, ZOOM

  ALEXANDRU CHIRVASITU (SUNY Buffalo)

  CENTERS AS UNIVERSAL GRADING GROUPS OF REPRESENTATION CATEGORIES

  It is a result of Müger that, for a compact group G, associating to every irreducible G-representation its central character identifies the Pontryagin dual of the center Z(G) with the universal group that, in a certain sense, labels the grading of the category...

• 2022-10-12, godz. 17:15, ZOOM

  FRANCESCO D'ANDREA (Università degli Studi di Napoli Federico II)

  THE CONVOLUTION ALGEBRA OF A TOLERANCE RELATION

  It is well known that a "bad" quotient space can be studied by associating to it the groupoid C*-algebra of its defining equivalence relation. A similar procedure for relations that are reflexive and symmetric but fail to be transitive leads to non-associat...

• 2022-10-05, godz. 17:15, ZOOM

  MARIUSZ TOBOLSKI (Uniwersytet Wrocławski)

  The Stone-von Neumann theorem for locally compact quantum groups

  The Stone-von Neumann theorem rigorously shows the equivalence between two fundamental approaches to quantum mechanics, notably, the matrix mechanics of Heisenberg and the wave mechanics of Schrödinger. This theorem was formulated by Mackey as a theorem about ce...

• 2022-06-15, godz. 17:15, ZOOM

  HENRI MOSCOVICI (Ohio State University)

  PROLATE SERENDIPITY AND THE ZEROS OF ZETA

  This talk is about the joint work with Alain Connes in which we display an isospectral family of Dirac-type operators whose ultraviolet spectrum matches remarkably well the zeros of the Riemann zeta function. ...

• 2022-06-08, godz. 17:15, ZOOM

  PAULO CARRILLO ROUSE (Université Paul Sabatier, Toulouse III)

  A DEFORMATION-GROUPOID APPROACH TO THE BAUM-CONNES ASSEMBLY MAP

  In a recent preprint, together with Bai-Ling Wang and Hang Wang, following the ideas of Connes and Moscovici, we give an explicit formula (in terms of a pairing of forms and currents) for the pairing of the left-hand side of the BC map of a discrete group and the periodic cyclic cohomology of the gr...

• 2022-06-01, godz. 17:15, ZOOM

  ELMAR SCHROHE (Leibniz Universität Hannover))

  ORDER PRESERVING AUTOMORPHISMS OF SHUBIN TYPE PSEUDODIFFERENTIAL OPERATORS

  We consider the algebra of all classical Shubin type pseudodifferential operators on Euclidean space. Following up on a remarkable result of Duistermaat and Singer (Comm. Pure Appl. Math. XXVIV:39-47, 1976) for the case of the usual pseudodifferential operators, we determine its order preserving aut...

• 2022-05-25, godz. 17:15, ZOOM

  EVGENIOS T. A. KAKARIADIS (Newcastle University)

  MORITA EQUIVALENCE FOR OPERATOR SYSTEMS

  In ring theory, Morita equivalence preserves many properties of the objects, and generalizes the isomorphism equivalence between commutative rings. A strong Morita equivalence for selfadjoint operator algebras was introduced by Rieffel in the 60s, and works as a correspondence between their represen...

• 2022-05-18, godz. 17:15, ZOOM

  JENS KAAD (Syddansk Universitet)

  GROUP COCYCLES ON LOOP GROUPS

  In this talk, we start out by reviewing the construction of central extensions of smooth loop groups and their relationship to the tame symbol of a pair of meromorphic functions on a Riemann surface. Our goal is then to introduce higher central extensions of smooth double loop groups. In this proces...

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