Lista referatów

• 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...

• 2022-05-11, godz. 17:15, ZOOM

  DAVID KYED (Syddansk Universitet)

  THE NON-COMMUTATIVE METRIC GEOMETRY OF QUANTUM SU(2)

  Rieffel's theory of compact quantum metric spaces provides an elegant non-commutative extension of the classical theory of compact metric spaces that is well aligned with Connes' non-commutative geometry. Recently, the quantum metric structure of q-deformed spaces has begun to unravel. In my...

• 2022-05-04, godz. 17:15, ZOOM

  MAXIM KONTSEVICH (IHÉS)

  ON PERIODS OF NONCOMMUTATIVE ALGEBRAS

  Connes' theory of integration says that a finitely summable Fredholm module defines a linear functional on periodic cyclic homology of an algebra defined over a subfield of complex numbers. Let us assume that the algebra is defined over rational numbers. Then one can show that, in this way, one ...

• 2022-04-27, godz. 17:15, ZOOM

  WOJCIECH SZYMAŃSKI (Syddansk Universitet)

  ON THE CONJUGACY OF MASAS IN GRAPH C*-ALGEBRAS

  We discuss the problem of conjugacy of MASAs in (purely infinite) graph C*-algebras. The main question we are interested in is inner versus outer conjugacy. To attack this problem, we employ a certain technique motivated by von Neumann algebra considerations. We illustrate it with some technically n...

• 2022-04-20, godz. 17:15, zoom

  PAULO CARRILLO ROUSE (Université Paul Sabatier, Toulouse III)

  AN NCG APPROACH TO INDEX THEORY FOR MANIFOLDS WITH CORNERS

  In this talk, I will review my joint work (published and on going) with Jean-Marie Lescure and Mario Velasquez, where we use groupoid and NCG techniques to study some problems in geometric analysis on manifolds with corners. In particular, I will review some K-theory computations (of the algebras of...

• 2022-04-13, godz. 17:15, zoom

  JOACHIM CUNTZ (Universität Münster)

  THE IMAGE OF BOTT PERIODICITY IN CYCLIC HOMOLOGY

  We analyze the relationship between Bott periodicity in K-theory and the natural periodicity of cyclic homology. This is a basis for understanding the multiplicativity, in odd dimensions, of a bivariant Chern-Connes character from K-theory to cyclic theory. ...

• 2022-04-06, godz. 17:15, zoom

  WALTER VAN SUIJLEKOM (Radboud Universiteit)

  NONCOMMUTATIVE SPACES AT FINITE RESOLUTION

  We extend the traditional framework of noncommutative geometry in order to deal with two types of approximation of metric spaces. On the one hand, we consider spectral truncations of geometric spaces, while on the other hand, we consider metric spaces up to finite resolution. In our approach, the tr...

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