North Atlantic Noncommutative Geometry Seminar

June 10, 2026, 5:15 p.m.
MASOUD KHALKHALI (Western University, London, Ontario, Canada)
NONCOMMUTATIVE GEOMETRY ON THE BERKOVICH PROJECTIVE LINE (NONCOMMUTATIVE GEOMETRY ON THE BERKOVICH PROJECTIVE LINE)
We discuss recent joint work with Damien Tageddine (J. Fractal Geom. 13, 2026) on noncommutative geometric structures associated to the Berkovich projective line. Starting from the action of p-adic Schottky groups, we construct Patterson-Sullivan measures …

June 3, 2026, 5:15 p.m.
ATUL P. GOTHE (IMPAN / Uniwersytet Warszawski, Warszawa, Poland)
A QUANTUM CW-COMPLEX STRUCTURE FOR QUANTUM REAL PROJECTIVE SPACES (A QUANTUM CW-COMPLEX STRUCTURE FOR QUANTUM REAL PROJECTIVE SPACES)
A CW-complex is a topological space which can be built up inductively by attaching n-balls along their boundary (n-1)-spheres. Quantum CW-complexes generalise the classical construction by dualising the pushouts of topological spaces to pullbacks of …

May 27, 2026, 5:15 p.m.
ANDRZEJ SITARZ (Uniwersytet Jagielloński, Kraków, Poland)
NONCOMMUTATIVE RICCI FLOW (NONCOMMUTATIVE RICCI FLOW)
The Ricci flow plays a central role in Riemannian geometry, both as a conceptual tool and as a driver of major breakthroughs. After introducing its fundamental ideas and classical applications, I will survey several existing …

May 20, 2026, 5:15 p.m.
GILLES G. DE CASTRO (Universidade Federal de Santa Catarina, Florianópolis, Brazil)
EXTENDED PATH HOMOMORPHISMS OF DIRECTED GRAPHS (EXTENDED PATH HOMOMORPHISMS OF DIRECTED GRAPHS)
Leavitt path algebras and graph C*-algebras are objects associated with directed graphs. They have deep connections with symbolic dynamics, and the former contains a class of rings that do not satisfy the Invariant Basis Number …

May 13, 2026, 5:15 p.m.
DANIEL VAN WYK (Fairfield University, Connecticut, USA)
GRADED LOCALLY FINITE AND GRADED JUST INFINITE STEINBERG ALGEBRAS (GRADED LOCALLY FINITE AND GRADED JUST INFINITE STEINBERG ALGEBRAS)
We will begin the talk by briefly reviewing the characterizations of locally finite and just infinite Leavitt path algebras, found by Abrams, Pino, and Molina. They consider Leavitt path algebras with the canonical Z-grading. After …

May 6, 2026, 5:15 p.m.
RALF MEYER (Universität Göttingen, Germany)
GRAPH MORPHISMS AS GROUPOID ACTORS (GRAPH MORPHISMS AS GROUPOID ACTORS)
A graph C*-algebra is known to be the groupoid C*-algebra of a certain groupoid, called the boundary-path groupoid. The boundary-path groupoid of a graph C*-algebra also has a universal property that is analogous to the …

April 29, 2026, 5:15 p.m.
MICHAEL HEINS (Technische Universiteit Delft, Netherlands)
CONVERGENT TWIST DEFORMATIONS (CONVERGENT TWIST DEFORMATIONS)
We discuss a functorial framework for the convergence of Drinfeld's Universal Deformation Formula on spaces of analytic vectors. Algebraically, the principal idea is that a Drinfeld twist induces formal deformations of any associative algebra on …

April 22, 2026, 5:15 p.m.
ANDRE KORNELL (New Mexico State University, Las Cruces, USA)
QUANTIZING DISCRETE STRUCTURES (QUANTIZING DISCRETE STRUCTURES)
A discrete structure consists of any number of sets and any number of maps and relations on those sets. This talk concerns a uniform approach to the quantization of classes of discrete structures. In other …

April 15, 2026, 5:15 p.m.
ALEXANDRU CHIRVASITU (SUNY Buffalo, USA)
MOST QUANTUM GRAPHS HAVE LIMITED (QUANTUM) SYMMETRY (MOST QUANTUM GRAPHS HAVE LIMITED (QUANTUM) SYMMETRY)
A quantum-graph structure on the ambient noncommutative space dual to the matrix algebra Mn can be encoded as an operator system S contained in Mn. Varying the operator system S while preserving the matrix size …

April 8, 2026, 5:15 p.m.
ELIZABETH A. PACHECO (Western Sydney University, Parramatta, Australia)
NEW REPRESENTATIONS OF LEAVITT PATH ALGEBRAS (NEW REPRESENTATIONS OF LEAVITT PATH ALGEBRAS)
A particular class of irreducible representations of Leavitt path algebras was defined by Chen in 2013. These representations have since been generalized but, until recently, these representations (together with projective modules based at sinks) were …

April 1, 2026, 5:15 p.m.
MURAD ÖZAYDIN (University of Oklahoma, Norman, USA)
A NON-COMMUTATIVE NULLSTELLENSATZ FOR LEAVITT PATH ALGEBRAS (A NON-COMMUTATIVE NULLSTELLENSATZ FOR LEAVITT PATH ALGEBRAS)
Hilbert's Nullstellensatz states that a quotient of the algebra of regular functions on an affine variety over an algebraically closed field is the algebra of regular functions on a (sub)variety if and only if its …

March 25, 2026, 5:15 p.m.
YANG LIU (SISSA, Trieste, Italy)
UNITAL EMBEDDINGS OF C*-ALGEBRAS THAT ONE CAN SEE (UNITAL EMBEDDINGS OF C*-ALGEBRAS THAT ONE CAN SEE)
Cuntz algebras On, n>1, are celebrated examples of a separable infinite simple C*-algebra with a number of fascinating properties. Their K-theory allows an embedding of Om in On whenever n−1 divides m−1. In 2009, Kawamura …

March 18, 2026, 5:15 p.m.
EVA-MARIA HEKKELMAN (Max-Planck-Institut für Mathematik, Bonn, Germany)
UNBOUNDED OPERATOR INTEGRALS AND NONCOMMUTATIVE QUANTUM FIELD THEORY (UNBOUNDED OPERATOR INTEGRALS AND NONCOMMUTATIVE QUANTUM FIELD THEORY)
In Noncommutative Geometry, operator integrals appear in abundance. However, since the involved operator arguments are typically unbounded, they do not neatly fit the usual theories of Multiple Operator Integrals (MOIs). To solve this problem, in …

March 11, 2026, 5:15 p.m.
DIMITRIS M. GERONTOGIANNIS (IMPAN, Warszawa, Poland)
QUANTUM ISOMETRY GROUPS OF LOG-LAPLACIANS ON CUNTZ-KRIEGER ALGEBRAS (QUANTUM ISOMETRY GROUPS OF LOG-LAPLACIANS ON CUNTZ-KRIEGER ALGEBRAS)
In recent work with Magnus Goffeng and Bram Mesland, we showed that Cuntz-Krieger algebras admit canonical spectral triples via the log-Laplacian. This talk concerns the quantum symmetries preserving this differential structure. They lead to a …

March 4, 2026, 5:15 p.m.
STEFAN WAGNER (Blekinge Tekniska Högskola, Karlskrona, Sweden)
NONCOMMUTATIVE PRINCIPAL BUNDLES AND CENTRAL EXTENSIONS (NONCOMMUTATIVE PRINCIPAL BUNDLES AND CENTRAL EXTENSIONS)
In Riemannian geometry, spin structures arise from lifting frame bundles along the universal covering of the structure group, with the existence and classification governed by cohomological obstructions. In this talk, I will present a noncommutative …