Topological spaces | 3-manifolds | Spheres | Homology theory

Homology sphere

In algebraic topology, a homology sphere is an n-manifold X having the homology groups of an n-sphere, for some integer . That is, and for all other i. Therefore X is a connected space, with one non-zero higher Betti number, namely, . It does not follow that X is simply connected, only that its fundamental group is perfect (see Hurewicz theorem). A rational homology sphere is defined similarly but using homology with rational coefficients. (Wikipedia).

Video thumbnail

Which homology spheres bound homology balls? - Francesco Lin

Which homology spheres bound homology balls? Speaker: Francesco Lin More videos on http://video.ias.edu

From playlist Mathematics

Video thumbnail

Homotopy type theory: working invariantly in homotopy theory -Guillaume Brunerie

Short talks by postdoctoral members Topic: Homotopy type theory: working invariantly in homotopy theory Speaker: Guillaume Brunerie Affiliation: Member, School of Mathematics Date: September 26, 2017 For more videos, please visit http://video.ias.edu

From playlist Mathematics

Video thumbnail

Homotopy animation

An interesting homotopy (in fact, an ambient isotopy) of two surfaces.

From playlist Algebraic Topology

Video thumbnail

Computing homology groups | Algebraic Topology | NJ Wildberger

The definition of the homology groups H_n(X) of a space X, say a simplicial complex, is quite abstract: we consider the complex of abelian groups generated by vertices, edges, 2-dim faces etc, then define boundary maps between them, then take the quotient of kernels mod boundaries at each

From playlist Algebraic Topology

Video thumbnail

Homotopy

Homotopy elements in the homotopy group π₂(S²) ≅ ℤ. Roman Gassmann and Tabea Méndez suggested some improvements to my original ideas.

From playlist Algebraic Topology

Video thumbnail

Introduction to Homotopy Theory- PART 1: UNIVERSAL CONSTRUCTIONS

The goal of this series is to develop homotopy theory from a categorical perspective, alongside the theory of model categories. We do this with the hope of eventually developing stable homotopy theory, a personal goal a passion of mine. I'm going to follow nLab's notes, but I hope to add t

From playlist Introduction to Homotopy Theory

Video thumbnail

Homotopy Group - (1)Dan Licata, (2)Guillaume Brunerie, (3)Peter Lumsdaine

(1)Carnegie Mellon Univ.; Member, School of Math, (2)School of Math., IAS, (3)Dalhousie Univ.; Member, School of Math April 11, 2013 In this general survey talk, we will describe an approach to doing homotopy theory within Univalent Foundations. Whereas classical homotopy theory may be des

From playlist Mathematics

Video thumbnail

Cylindrical contact homology as a well-defined homology? - Joanna Nelson

Joanna Nelson Institute for Advanced Study; Member, School of Mathematics February 7, 2014 In this talk I will explain how the heuristic arguments sketched in literature since 1999 fail to define a homology theory. These issues will be made clear with concrete examples and we will explore

From playlist Mathematics

Video thumbnail

Lie Groups and Lie Algebras: Lesson 34 -Introduction to Homotopy

Lie Groups and Lie Algebras: Introduction to Homotopy In order to proceed with Gilmore's study of Lie groups and Lie algebras we now need a concept from algebraic topology. That concept is the notion of homotopy and the Fundamental Group of a topological space. In this lecture we provide

From playlist Lie Groups and Lie Algebras

Video thumbnail

Matthew Hedden - Irreducible homology S1xS2's which aren't zero surgeries on a knot

June 20, 2018 - This talk was part of the 2018 RTG mini-conference Low-dimensional topology and its interactions with symplectic geometry I'll discuss constructions of manifolds with the homology of S^1xS^2 which don't arise as Dehn surgery on a knot in S^3. Our examples have weight one

From playlist 2018 RTG mini-conference on low-dimensional topology and its interactions with symplectic geometry I

Video thumbnail

Homology cobordism and triangulations – Ciprian Manolescu – ICM2018

Geometry | Topology Invited Lecture 5.5 | 6.1 Homology cobordism and triangulations Ciprian Manolescu Abstract: The study of triangulations on manifolds is closely related to understanding the three-dimensional homology cobordism group. We review here what is known about this group, with

From playlist Geometry

Video thumbnail

Duality for Rabinowitz-Floer homology - Alex Oancea

IAS/PU-Montreal-Paris-Tel-Aviv Symplectic Geometry Topic: Duality for Rabinowitz-Floer homology Speaker: Alex Oancea Affiliation: Institut de Mathématiques de Jussieu-Paris Rive Gauche Date: May 27, 2020 For more video please visit http://video.ias.edu

From playlist PU/IAS Symplectic Geometry Seminar

Video thumbnail

Contact non-squeezing via selective symplectic homology - Igor Uljarević

Joint IAS/Princeton/Montreal/Paris/Tel-Aviv Symplectic Geometry Zoominar Topic: Contact non-squeezing via selective symplectic homology Speaker: Igor Uljarević Affiliation: University of Belgrade Date: October 14, 2022 I will introduce a new version of symplectic homology that resembles

From playlist Mathematics

Video thumbnail

Stable Homotopy Seminar, 15: Dualizable and invertible spectra

I present the useful fact that spectra are generated by finite complexes under filtered homotopy colimits. I then define Spanier-Whitehead duality, which is a special case of a notion of duality that exists in any closed symmetric monoidal category. Two natural classes of spectra rise from

From playlist Stable Homotopy Seminar

Video thumbnail

Henry Adams - Bridging applied and geometric topology

38th Annual Geometric Topology Workshop (Online), June 15-17, 2021 Henry Adams, Colorado State University Title: Bridging applied and geometric topology Abstract: I will advertise open questions in applied topology for which tools from geometric topology are relevant. If a point cloud is

From playlist 38th Annual Geometric Topology Workshop (Online), June 15-17, 2021

Video thumbnail

Henry Adams (8/30/21): Vietoris-Rips complexes of hypercube graphs

Questions about Vietoris-Rips complexes of hypercube graphs arise naturally from problems in genetic recombination, and also from Kunneth formulas for persistent homology with the sum metric. We describe the homotopy types of Vietoris-Rips complexes of hypercube graphs at small scale param

From playlist Beyond TDA - Persistent functions and its applications in data sciences, 2021

Video thumbnail

Homomorphisms in abstract algebra

In this video we add some more definition to our toolbox before we go any further in our study into group theory and abstract algebra. The definition at hand is the homomorphism. A homomorphism is a function that maps the elements for one group to another whilst maintaining their structu

From playlist Abstract algebra

Video thumbnail

What is an i-dimensional hole in a space?

What is an i-dimensional hole in a space? I describe how topology provides (at least) two answers to this question --- both the homotopy groups and the homology groups of that space. I give some intuition for what an i-dimensional hole is, and I give some intuition for how homotopy groups

From playlist Topology - Henry Adams - 2022

Related pages

Icosahedral symmetry | Topological manifold | 3-sphere | Spherical 3-manifold | If and only if | Hurewicz theorem | Binary icosahedral group | Casson invariant | Betti number | Algebraic topology | Suspension (topology) | Quaternion | Quotient space (topology) | Moore space (algebraic topology) | Brieskorn manifold | Alternating group | Dodecahedron | Eilenberg–MacLane space | Hyperbolic 3-manifold | Connected sum | Egbert Brieskorn | SL2(R) | Icosahedron | Symmetry group | Connected space | Homology manifold | Sphere | Embedding | Henri Poincaré | Triangulation (topology) | Perfect group | Shape of the universe | Fundamental group | Manifold | Seifert–Weber space | Seifert fiber space | Simplicial complex | Dehn surgery