A covering of a topological space X is a topological space Y together with a continuous surjective map from X to Y that is locally bi-continuos. The infinite spiral is for example a covering of the circle. Notice how every path on the circle can be lifted to the spiral. If a coveri
From playlist Algebraic Topology
David Cimasoni : Covering spaces and spanning trees
Abstract: The aim of this talk is to show how basic notions traditionally used in the study of "knotted embeddings in dimensions 3 and 4", such as covering spaces and representation theory, can have non-trivial applications in combinatorics and statistical mechanics. For example, we will s
From playlist Topology
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From playlist Biology
Introduction to Spanning Trees
This video introduces spanning trees. mathispower4u.com
From playlist Graph Theory (Discrete Math)
Vertex Covers and Vertex Covering Numbers | Graph Theory
We introduce vertex covers, minimum vertex covers, and vertex covering numbers! We'll see some examples and non-examples of vertex covers, as well as minimum vertex covers and some that aren't minimum. The number of vertices in a minimum vertex cover is called the vertex covering number of
From playlist Graph Theory
Sites/Coverings part 2: Grothendieck Topologies
Definition of a Grothendieck topology. This is just the axiomatization of coverings.
From playlist Sites, Coverings and Grothendieck Topologies
Introduction to Fiber Bundles part 1: Definitions
We give the definition of a fiber bundle with fiber F, trivializations and transition maps. This is a really basic stuff that we use a lot. Here are the topics this sets up: *Associated Bundles/Principal Bundles *Reductions of Structure Groups *Steenrod's Theorem *Torsor structure on arith
From playlist Fiber bundles
Vertex Covering Number of Complete Graphs | Graph Theory Exercises
We discuss and prove the vertex covering number of a complete graph Kn is n-1. That is, the minimum number of vertices needed to cover a complete graph is one less than its number of vertices. This is because, put simply, if we are missing at least 2 vertices in our attempted vertex cover,
From playlist Graph Theory Exercises
What is a Spanning Subgraph? | Graph Theory
What is a spanning subgraph? We go over this special type of subgraph in today's math lesson! Recall that a graph is an ordered pair G = ( V(G), E(G) ) with vertex set V and edge set E. Another graph, H = ( V(H), E(H) ) is a subgraph of G if and only if V(H) is a subset of V(G) and E(H) is
From playlist Graph Theory
Transversality and super-rigidity in Gromov-Witten Theory (Lecture - 03) by Chris Wendl
J-Holomorphic Curves and Gromov-Witten Invariants DATE:25 December 2017 to 04 January 2018 VENUE:Madhava Lecture Hall, ICTS, Bangalore Holomorphic curves are a central object of study in complex algebraic geometry. Such curves are meaningful even when the target has an almost complex stru
From playlist J-Holomorphic Curves and Gromov-Witten Invariants
Mark Hughes: Branched Coverings Over Surface Braids and (Broken) Lefschetz Fibrations
Mark Hughes, Brigham Young University Title: Branched Coverings Over Surface Braids and (Broken) Lefschetz Fibrations on Non- compact 4-Manifold In this talk I will discuss a construction of Lefschetz type fibrations on 4–manifolds via coverings branched over braided surfaces. When applied
From playlist 39th Annual Geometric Topology Workshop (Online), June 6-8, 2022
Branched complex projective structures on surfaces (Lecture 02) by Stefano Francaviglia
DISCUSSION MEETING SURFACE GROUP REPRESENTATIONS AND PROJECTIVE STRUCTURES ORGANIZERS: Krishnendu Gongopadhyay, Subhojoy Gupta, Francois Labourie, Mahan Mj and Pranab Sardar DATE: 10 December 2018 to 21 December 2018 VENUE: Ramanujan Lecture Hall, ICTS Bangalore The study of spaces o
From playlist Surface group representations and Projective Structures (2018)
Transversality and super-rigidity in Gromov-Witten Theory (Lecture – 02) by Chris Wendl
J-Holomorphic Curves and Gromov-Witten Invariants DATE:25 December 2017 to 04 January 2018 VENUE:Madhava Lecture Hall, ICTS, Bangalore Holomorphic curves are a central object of study in complex algebraic geometry. Such curves are meaningful even when the target has an almost complex stru
From playlist J-Holomorphic Curves and Gromov-Witten Invariants
Michal Pilipczuk: Introduction to parameterized algorithms, lecture I
The mini-course will provide a gentle introduction to the area of parameterized complexity, with a particular focus on methods connected to (integer) linear programming. We will start with basic techniques for the design of parameterized algorithms, such as branching, color coding, kerneli
From playlist Summer School on modern directions in discrete optimization
Proving super-polynomial lower bounds for syntactic multilinear branching programs by Ramya C
Discussion Meeting Workshop on Algebraic Complexity Theory  ORGANIZERS Prahladh Harsha, Ramprasad Saptharishi and Srikanth Srinivasan DATE & TIME 25 March 2019 to 29 March 2019 VENUE Madhava Lecture Hall, ICTS Bangalore Algebraic complexity aims at understanding the computationa
From playlist Workshop on Algebraic Complexity Theory 2019
Michael HUTCHINGS - 3/3 Obstruction Bundle Gluing
There are easy examples showing that classical transversality methods cannot always succeed for multiply covered holomorphic curves, but the situation is not hopeless. In this talk I will describe two approaches that sometimes lead to interesting results: (1) analytic perturbation theory,
From playlist 2015 Summer School on Moduli Problems in Symplectic Geometry
Super-rigidity and bifurcations of embedded curves in Calabi-Yau 3-folds - Mohan Swaminathan
Joint IAS/Princeton/Montreal/Paris/Tel-Aviv Symplectic Geometry Topic: Super-rigidity and bifurcations of embedded curves in Calabi-Yau 3-folds Speaker: Mohan Swaminathan Affiliation: Princeton Date: June 25, 2021 I will describe my recent work, joint with Shaoyun Bai, which studies a
From playlist Mathematics
Branched complex projective structures on surfaces (Lecture 01) by Stefano Francaviglia
DISCUSSION MEETING SURFACE GROUP REPRESENTATIONS AND PROJECTIVE STRUCTURES ORGANIZERS: Krishnendu Gongopadhyay, Subhojoy Gupta, Francois Labourie, Mahan Mj and Pranab Sardar DATE: 10 December 2018 to 21 December 2018 VENUE: Ramanujan Lecture Hall, ICTS Bangalore The study of spaces o
From playlist Surface group representations and Projective Structures (2018)
From representations of the symmetric group to branched covers of the disk - Amitai Netser Zernik
Short talks by postdoctoral members Topic: From representations of the symmetric group to branched covers of the disk Speaker: Amitai Netser Zernik Affiliation: Member, School of Mathematics Date: October 4, 2017 For more videos, please visit http://video.ias.edu
From playlist Mathematics
We don't know what a tree is (and this video won't tell you)
Offset your carbon footprint with Wren! They'll protect 5 extra acres of rainforest for each of the first 100 people who sign up at https://www.wren.co/join/minuteearth. It turns out that defining what is and isn't a “tree” is way harder than it seems. LEARN MORE ************** To learn m
From playlist This Is Not A Playlist