Algebra Seminar

Linköping Algebra Seminar is a seminar series at the Department of Mathematics. Erik Darpö (ALGD) is the organiser.

Time and place

The seminars usually take place on Thursdays, 10:15-12:00 in the Hopningspunkten seminar room, located in the B-house, entrance 23, floor 2, Campus Valla in Linköping.

Upcoming seminars

Thursday 15 June Axel Tiger Norkvist, Departement of Mathematics, Linköping University

Title: The Noncommutative Geometry of Real Calculi

Abstract: The profound connection observed between algebra and geometry during the 1940s and beyond has transformed both fields, with extensive exploration of commutative algebras and their relationship to topological spaces. In the 1980s, mathematicians recognized the value of applying a geometric perspective to noncommutative algebras, leading to remarkable advancements in the field of noncommutative geometry. This talk focuses on Real Calculi, a derivation-based approach that generalizes aspects of Riemannian Geometry to noncommutative algebras, and explores some of the challenges that arise in the process.

Previous seminars

Thursday 25 May Axel Hultman, Departement of Mathematics, Linköping University

Title: Coxeter groups

Abstract:  We shall get acquainted with Coxeter groups from a perspective heavily slanted toward combinatorics. Along the way, algebraic and geometric structures will show up. Objects like Schubert varieties, Hecke algebras, and Kazhdan-Lusztig polynomials may appear. We hope (sometimes perhaps too naïvely) that the combinatorics of Coxeter groups have interesting things to say about them. Some ideas in this direction will be presented.

Thursday 23 March  Axel Hultman, Departement of Mathematics, Linköping University

Title: Coxeter groups

Abstract: We shall get acquainted with Coxeter groups from a perspective heavily slanted toward combinatorics. Along the way, algebraic and geometric structures will show up. Objects like Schubert varieties, Hecke algebras, and Kazhdan-Lusztig polynomials may appear. We hope (sometimes perhaps too naïvely) that the combinatorics of Coxeter groups have interesting things to say about them. Some ideas in this direction will be presented.

Thursday 9 March Daniel Lännström, Departement of Mathematics, Linköping University

Title: Graded Ring Theory and Leavitt path algebras

Abstract: In this talk I will discuss my research concerned with so-called epsilon-strongly group graded rings and Leavitt path algebras. Unlike in many common general reference works in algebra, we will NOT assume that our rings are equipped with a multiplicative identity element. I will begin my talk by presenting different ways to define local units for non-unital rings. Next, I will detail some background on Leavitt path algebras, which can be seen as algebraic analouge of certain graph C^*-algebras. This area of research has seen a lot of recent activity which prompted the inclusion of Leavitt path algebras in the 2020 Mathematics Subject Classification (MSC2020). I will also present some important work from the 1980s by Dade about strongly graded rings and how that relates to the recently introduce notion of epsilon-strongly graded rings. Finally, I will talk about some joint research with P. Lundström (previously known as P. Nystedt), J. Öinert and S. Wagner.

Thursday 16 February Joakim Arnlind, Departement of Mathematics, Linköping University, part 2

Title: Noncommutative Levi-Civita connections

Abstract:  Over the last 40 years, it has become apparent that it is fruitful to extend geometric notions to the setting of noncommutative algebras; both from a mathematical point of view, when studying geometric spaces with few (or no) interesting functions, and from a physical point of view, where noncommutative geometry lies at the heart of constructing theories of quantum gravity.

While the topological aspects of noncommutative geometry are by now fairly well studied, the Riemannian aspects are far less understood, although a lot of progress has been made during the last decade. In particular, the role of the Levi-Civita connection, which is an important object in Riemannian geometry, as well as a fundamental one in general relativity, is not completely understood.

In this series of lectures, I will present an algebraic view on Riemannian geometry, illustrating how one can make sense of e.g. differential forms, vector bundles, metrics and connections in a noncommutative setting. Moreover, I will present material related to the work I've done on the existence and uniqueness of Levi-Civita connections for noncommutative vector bundles.

Thursday 26 January Joakim Arnlind, Departement of Mathematics, Linköping University, part 1

Title: Noncommutative Levi-Civita connections

Abstract:  Over the last 40 years, it has become apparent that it is fruitful to extend geometric notions to the setting of noncommutative algebras; both from a mathematical point of view, when studying geometric spaces with few (or no) interesting functions, and from a physical point of view, where noncommutative geometry lies at the heart of constructing theories of quantum gravity.

While the topological aspects of noncommutative geometry are by now fairly well studied, the Riemannian aspects are far less understood, although a lot of progress has been made during the last decade. In particular, the role of the Levi-Civita connection, which is an important object in Riemannian geometry, as well as a fundamental one in general relativity, is not completely understood.

In this series of lectures, I will present an algebraic view on Riemannian geometry, illustrating how one can make sense of e.g. differential forms, vector bundles, metrics and connections in a noncommutative setting. Moreover, I will present material related to the work I've done on the existence and uniqueness of Levi-Civita connections for noncommutative vector bundles.

Contact

Organisation