Karen Vogtmann, Lecture I - 10 February 2015
Karen Vogtmann (U. of Warwick, UK and Cornell University, USA) - Lecture I http://www.crm.sns.it/course/4037/ Automorphism groups of free groups bear similarities to both lattices in Lie groups and to surface mapping class groups. In this minicourse we will explore the cohomology of thes
From playlist Algebraic topology, geometric and combinatorial group theory - 2015
Karen Vogtmann, Lecture II - 12 February 2015
Karen Vogtmann (U. of Warwick, UK and Cornell University, USA) - Lecture II http://www.crm.sns.it/course/4037/ Automorphism groups of free groups bear similarities to both lattices in Lie groups and to surface mapping class groups. In this minicourse we will explore the cohomology of thes
From playlist Algebraic topology, geometric and combinatorial group theory - 2015
Jacob explains the fundamental concepts in group theory of what groups and subgroups are, and highlights a few examples of groups you may already know. Abelian groups are named in honor of Niels Henrik Abel (https://en.wikipedia.org/wiki/Niels_Henrik_Abel), who pioneered the subject of
From playlist Basics: Group Theory
Alfred Geroldinger: A characterization of class groups via sets of lengths
Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b
From playlist Combinatorics
This lecture is part of an online math course on group theory. We review free abelian groups, then construct free (non-abelian) groups, and show that they are given by the set of reduced words, and as a bonus find that they are residually finite.
From playlist Group theory
Combinatorial Identities via both Algebraic and Combinatorial Proof [Discrete Math Class]
This video is not like my normal uploads. This is a supplemental video from one of my courses that I made in case students had to quarantine. This is a follow up to previous a video introducing combinatorial objects (in particular k-permutations and k-subsets) and a video about the sum and
From playlist Discrete Mathematics Course
What is a Group? | Abstract Algebra
Welcome to group theory! In today's lesson we'll be going over the definition of a group. We'll see the four group axioms in action with some examples, and some non-examples as well which violate the axioms and are thus not groups. In a fundamental way, groups are structures built from s
From playlist Abstract Algebra
Chapter 5: Quotient groups | Essence of Group Theory
Quotient groups is a very important concept in group theory, because it has paramount importance in group homomorphisms (connection with the isomorphism theorem(s)). With this video series, abstract algebra needs not be abstract - one can easily develop intuitions for group theory! In fac
From playlist Essence of Group Theory
Introduction to additive combinatorics lecture 10.1 --- the structure and properties of Bohr sets.
An important informal idea in additive combinatorics is that of a "structured" set. One example of a class of sets that are rich in additive structure is the class of Bohr sets, which play the role in general finite Abelian groups that subspaces play in the special case of groups of the fo
From playlist Introduction to Additive Combinatorics (Cambridge Part III course)
Introduction to additive combinatorics lecture 1.0 --- What is additive combinatorics?
This is an introductory video to a 16-hour course on additive combinatorics given as part of Cambridge's Part III mathematics course in the academic year 2021-2. After a few remarks about practicalities, I informally discuss a few open problems, and attempt to explain what additive combina
From playlist Introduction to Additive Combinatorics (Cambridge Part III course)
Nezhla Aghaei - Combinatorial Quantisation of Supergroup Chern-Simons Theory
Chern-Simons Theories with gauge super-groups appear naturally in string theory and they possess interesting applications in mathematics, e.g. for the construction of knot and link invariants. In my talk, I will review the framework of combinatorial quantization of Chern Simons theory and
From playlist Workshop on Quantum Geometry
Adélie Garin : From Trees to Barcodes and Back Again: Combinatorial and Geometric Perspectives
Title: From Trees to Barcodes and Back Again: Combinatorial and Geometric Perspectives Abstract: Methods of topological data analysis have been successfully applied in a wide range of fields to provide useful summaries of the structure of complex data sets in terms of topological descript
From playlist AATRN 2022
Singular Hodge Theory for Combinatorial Geometries by Jacob Matherne
PROGRAM COMBINATORIAL ALGEBRAIC GEOMETRY: TROPICAL AND REAL (HYBRID) ORGANIZERS: Arvind Ayyer (IISc, India), Madhusudan Manjunath (IITB, India) and Pranav Pandit (ICTS-TIFR, India) DATE & TIME: 27 June 2022 to 08 July 2022 VENUE: Madhava Lecture Hall and Online Algebraic geometry is t
From playlist Combinatorial Algebraic Geometry: Tropical and Real (HYBRID)
Connecting tropical intersection theory with polytope algebra in types A and B by Alex Fink
PROGRAM COMBINATORIAL ALGEBRAIC GEOMETRY: TROPICAL AND REAL (HYBRID) ORGANIZERS Arvind Ayyer (IISc, India), Madhusudan Manjunath (IITB, India) and Pranav Pandit (ICTS-TIFR, India) DATE & TIME: 27 June 2022 to 08 July 2022 VENUE: Madhava Lecture Hall and Online Algebraic geometry is t
From playlist Combinatorial Algebraic Geometry: Tropical and Real (HYBRID)
Matt SZCZESNY - Toric Hall Algebras and infinite-dimentional Lie algebras
The process of counting extensions in categories yields an associative (and sometimes Hopf) algebra called a Hall algebra. Applied to the category of Feynman graphs, this process recovers the Connes-Kreimer Hopf algebra. Other examples abound, yielding various combinatorial Hopf algebras.
From playlist Algebraic Structures in Perturbative Quantum Field Theory: a conference in honour of Dirk Kreimer's 60th birthday
Global symmetry from local information: The Graph Isomorphism Problem – László Babai – ICM2018
Combinatorics | Mathematical Aspects of Computer Science Invited Lecture 13.4 | 14.5 Global symmetry from local information: The Graph Isomorphism Problem László Babai Abstract: Graph Isomorphism (GI) is one of a small number of natural algorithmic problems with unsettled complexity stat
From playlist Combinatorics
Algebraic combinatorics: applications to statistical mechanics and complexity theory - Greta Panova
Short proofs are hard to find (joint work w/ Toni Pitassi and Hao Wei) - Ian Mertz Computer Science/Discrete Mathematics Seminar II Topic: Short proofs are hard to find (joint work w/ Toni Pitassi and Hao Wei) Speaker: Ian Mertz Affiliation: University of Toronto Date: December 5, 2017 F
From playlist Mathematics
Arik Wilbert: Two block Springer fibers and Springer repres
The lecture was held within the framework of the Hausdorff Trimester Program: Symplectic Geometry and Representation Theory. Abstract: We explain how to construct an explicit topological model for every two-block Springer fiber of type C and D. These so-called topological Springer fibers
From playlist HIM Lectures: Trimester Program "Symplectic Geometry and Representation Theory"
Joseph Bengeloun - Quantum Mechanics of Bipartite Ribbon Graphs...
Quantum Mechanics of Bipartite Ribbon Graphs: A Combinatorial Interpretation of the Kronecker Coefficient. The action of subgroups on a product of symmetric groups allows one to enumerate different families of graphs. In particular, bipartite ribbon graphs (with at most edges) enumerate
From playlist Combinatorics and Arithmetic for Physics: 02-03 December 2020
Pablo Shmerkin: Additive combinatorics methods in fractal geometry - lecture 2
In the last few years ideas from additive combinatorics were applied to problems in fractal geometry and led to progress on some classical problems, particularly on the smoothness of Bernoulli convolutions and other self-similar measures. We will introduce some of these tools from additive
From playlist Combinatorics