In mathematics, specifically in category theory, a semi-abelian category is a pre-abelian category in which the induced morphism is a bimorphism, i.e., a monomorphism and an epimorphism, for every morphism . (Wikipedia).
We give a buttload of definitions for morphisms on various categories of complexes. The derived category of an abelian category is a category whose objects are cochain complexes and whose morphisms I describe in this video.
From playlist Derived Categories
Semi-coarse Spaces, Homotopy [Jonathan Treviño-Marroquín]
Semi-coarse spaces is an alternative to study (undirected) graphs through large-scale geometry. In this video, we present the structure and a homotopy what we worked on. In the final part, we look at the fundamental homotopy group of cyclic graphs.
From playlist Contributed Videos
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
Kazuya Kato - Logarithmic abelian varieties
Correction: The affiliation of Lei Fu is Tsinghua University. This is a joint work with T. Kajiwara and C. Nakayama. Logarithmic abelian varieties are degenerate abelian varieties which live in the world of log geometry of Fontaine-Illusie. They have group structures which do not exist in
From playlist Conférence « Géométrie arithmétique en l’honneur de Luc Illusie » - 5 mai 2021
Every Group of Order Five or Smaller is Abelian Proof
Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Every Group of Order Five or Smaller is Abelian Proof. In this video we prove that if G is a group whose order is five or smaller, then G must be abelian.
From playlist Abstract Algebra
AlgTopReview4: Free abelian groups and non-commutative groups
Free abelian groups play an important role in algebraic topology. These are groups modelled on the additive group of integers Z, and their theory is analogous to the theory of vector spaces. We state the Fundamental Theorem of Finitely Generated Commutative Groups, which says that any such
From playlist Algebraic Topology
Aleksi Saarela : k-abelian complexity and fluctuation
Abstract : Words u and v are defined to be k-abelian equivalent if every factor of length at most k appears as many times in u as in v. The k-abelian complexity function of an infinite word can then be defined so that it maps a number n to the number of k-abelian equivalence classes of len
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
Lucia Mocz: A new Northcott property for Faltings height
Abstract: The Faltings height is a useful invariant for addressing questions in arithmetic geometry. In his celebrated proof of the Mordell and Shafarevich conjectures, Faltings shows the Faltings height satisfies a certain Northcott property, which allows him to deduce his finiteness stat
From playlist Algebraic and Complex Geometry
Nick Addington - Rational points and derived equivalence - WAGON
For smooth projective varieties over Q, is the existence of a rational point preserved under derived equivalence? First I'll discuss why this question is interesting, and what is known. Then I'll show that the answer is no, giving two counterexamples: an abelian variety and a torsor over i
From playlist WAGON
Quiver moduli and applications, Markus Reineke (Bochum), Lecture 3
Quiver moduli spaces are algebraic varieties encoding the continuous parameters of linear algebra type classification problems. In recent years their topological and geometric properties have been explored, and applications to, among others, Donaldson-Thomas and Gromov-Witten theory have
From playlist Felix Klein Lectures 2020: Quiver moduli and applications, Markus Reineke (Bochum)
Mark Grant (10/22/20): Bredon cohomology and LS-categorical invariants
Title: Bredon cohomology and LS-categorical invariants Abstract: Farber posed the problem of describing the topological complexity of aspherical spaces in terms of algebraic invariants of their fundamental groups. In Part One of this talk, I’ll discuss joint work with Farber, Lupton and O
From playlist Topological Complexity Seminar
Arend Bayer: Stability and applications to birational and hyperkaehler geometry - lecture 1
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 Algebraic and Complex Geometry
Introduction to p-adic Hodge theory (Lecture 4) by Denis Benois
PROGRAM PERFECTOID SPACES ORGANIZERS: Debargha Banerjee, Denis Benois, Chitrabhanu Chaudhuri, and Narasimha Kumar Cheraku DATE & TIME: 09 September 2019 to 20 September 2019 VENUE: Madhava Lecture Hall, ICTS, Bangalore Scientific committee: Jacques Tilouine (University of Paris, France
From playlist Perfectoid Spaces 2019
Lutz Hille: On the derived category in global dimension two joint with David Ploog
Motivated by joint work with Perling on rational surfaces and results of Böhning, von Bothmer and Sosna on surfaces of general type, we are interested in a deeper and more detailed understanding of the derived category of an abelian category of global dimension two. In fact, we can describ
From playlist HIM Lectures: Junior Trimester Program "Algebraic Geometry"
On the notion of λ-connection - Carlos Simpson
Geometry and Arithmetic: 61st Birthday of Pierre Deligne Carlos Simpson University of Nice October 18, 2005 Pierre Deligne, Professor Emeritus, School of Mathematics. On the occasion of the sixty-first birthday of Pierre Deligne, the School of Mathematics will be hosting a four-day confe
From playlist Pierre Deligne 61st Birthday