Link do kanału youtube: https://www.youtube.com/channel/UCnHfrrAKk9Jaaw8oC2s_dSQ

Zoom platform link: https://us02web.zoom.us/j/83662713532?pwd=MFpVS1NlQkt4THVtMGdYNTR2Ym93UT09

Meeting ID: 836 6271 3532 Passcode: 764579

- Paul F. Baum
- Francesco D'Andrea
- Ludwik Dąbrowski
- Søren Eilers
- Piotr M. Hajac
- Frédéric Latrémolière
- Ryszard Nest
- Marc A. Rieffel
- Andrzej Sitarz
- Wojciech Szymański
- Adam Wegert

2022-11-23, 17:15, 405 IMPAN & ZOOM

MARC A. RIEFFEL (UC Berkeley)

**CONVERGENCE OF FOURIER TRUNCATIONS**We generalize the Fejer-Riesz operator systems defined for the circle group by Connes and van Suijlekom to the setting of compact matrix quantum groups and their ergodic actions on C*-algebras. These truncations form filtrations of the containing C*-algebra. When the truncations and the containing C...

2022-11-16, 17:15, 405 IMPAN & ZOOM

LUDWIK DĄBROWSKI (SISSA)

**SPECTRAL METRIC AND EINSTEIN FUNCTIONALS**Using the Wodzicki residue, in terms of the Laplace operator, we define two bilinear functionals on vector fields. Their densities yield, respectively, the metric tensor and the Einstein tensor on an even-dimensional Riemannian manifold. Then, in terms of the Dir...

2022-11-09, 17:15, 405 IMPAN & ZOOM

BRAM MESLAND (Universiteit Leiden)

**CURVATURE FOR DIFFERENTIABLE HILBERT MODULES**In this talk, we introduce the curvature of densely defined universal connections on Hilbert C*-modules, relative to a spectral triple, leading to a well defined curvature operator. Algebraically, this curvature can be interpreted as the defect of the unbounded Kasparov product to commute with the o...

2022-11-02, 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, 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, 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, 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, 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, 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, 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...