Paul Shafer:Reverse mathematics of Caristi's fixed point theorem and Ekeland's variational principle
The lecture was held within the framework of the Hausdorff Trimester Program: Types, Sets and Constructions. Abstract: Caristi's fixed point theorem is a fixed point theorem for functions that are controlled by continuous functions but are necessarily continuous themselves. Let a 'Caristi
From playlist Workshop: "Proofs and Computation"
In this video, I prove a very neat result about fixed points and give some cool applications. This is a must-see for calculus lovers, enjoy! Old Fixed Point Video: https://youtu.be/zEe5J3X6ISE Banach Fixed Point Theorem: https://youtu.be/9jL8iHw0ans Continuity Playlist: https://www.youtu
From playlist Calculus
In this video we prove the Lefschetz fixed point theorem assuming some properties of our cohomology theory. These notes were really useful as a graduate student, some of them are down now, but I think these notes I had came from here: http://mathsci.kaist.ac.kr/~jinhyun/useful.html
From playlist Riemann Hypothesis
Lefschetz Fixed Point Theorem example
Here we give an example of how to use the Lefschetz fixed point theorem. These notes were really useful as a graduate student, some of them are down now, but I think these notes I had came from here: http://mathsci.kaist.ac.kr/~jinhyun/useful.html
From playlist Riemann Hypothesis
Wormholes Explained – Breaking Spacetime
Are wormholes real or are they just magic disguised as physics and maths? And if they are real how do they work and where can we find them? Sources and further reading: https://authors.library.caltech.edu/9262/1/MORprl88.pdf http://www.cmp.caltech.edu/refael/league/thorne-morris.pdf OUR
From playlist Our Best Stuff
Fixed and Periodic Points | Nathan Dalaklis
Fixed Points and Periodic points are two mathematical objects that come up all over the place in Dynamical systems, Differential equations, and surprisingly in Topology as well. In these videos, I introduce the concepts of fixed points and periodic points and gradually build to a proof of
From playlist The New CHALKboard
Math 131 092616 Heine Borel, Connected Sets, Limits in Metric Spaces
Heine-Borel Theorem, connected sets, limits in metric spaces, uniqueness of limits
From playlist Course 7: (Rudin's) Principles of Mathematical Analysis
Topics in Combinatorics lecture 3.0 --- Crossing numbers and point-line incidences
Suppose you have n points and m lines in the plane. A point-line incidence is a pair (P,L) where P is one of the points and L is one of the lines. How many point-line incidences can there be, given m and n? This question is answered by the Szemerédi-Trotter theorem: the answer, up to a mul
From playlist Topics in Combinatorics (Cambridge Part III course)
Math 131 111416 Sequences of Functions: Pointwise and Uniform Convergence
Definition of pointwise convergence. Examples, nonexamples. Pointwise convergence does not preserve continuity, differentiability, or integrability, or commute with differentiation or integration. Uniform convergence. Cauchy criterion for uniform convergence. Weierstrass M-test to imp
From playlist Course 7: (Rudin's) Principles of Mathematical Analysis
Fixed points in digital topology
A talk given by Chris Staecker at King Mongkut's University of Technology Thonburi, Bangkok, Thailand, on October 11 2019. This is the second in a series of 3 talks given at KMUTT. Includes an introduction to graph-theoretical ("Rosenfeld style") digital topology, and some basic results a
From playlist Research & conference talks
Classical spherical trigonometry | Universal Hyperbolic Geometry 36 | NJ Wildberger
This video presents a summary of classical spherical trigonometry. First we define spherical distance between two points on a sphere, then the angle between two lines on a sphere (i.e. great circles). After a quick reminder of the circular functions cos,sin and tan, we present the main la
From playlist Universal Hyperbolic Geometry
Axioms for the fixed point index of an n-valued map
A research talk I gave at KU Leuven Kulak in Kortrijk, Belgium on June 4, 2019, at the conference on Nielsen Theory and Related Topics. The first 20 minutes is mostly about the Euler characteristic, and should be understandable to all mathematicians. The audience was other researchers in t
From playlist Research & conference talks
Piotr Przytycki: Torsion groups do not act on 2-dimensional CAT(0) complexes
We show, under mild hypotheses, that if each element of a finitely generated group acting on a 2-dimensional CAT(0) complex has a fixed point, then the action is trivial. In particular, all actions of finitely generated torsion groups on such complexes are trivial. As an ingredient, we pro
From playlist Geometry
Intro to Nielsen fixed point theory
A talk given by Chris Staecker at King Mongkut's University of Technology Thonburi, Bangkok, Thailand, on October 10 2019. Covers basic definitions and results of Nielsen fixed point theory, plus a few minutes about Nielsen-type theories for coincidence and periodic points. Should be und
From playlist Research & conference talks
Proving Brouwer's Fixed Point Theorem | Infinite Series
Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi There is a proof for Brouwer's Fixed Point Theorem that uses a bridge - or portal - between geometry and algebra. Tweet at us! @pbsinfinite Facebook: facebook.com/pbs
From playlist An Infinite Playlist
Group theory 4: Lagrange's theorem
This is lecture 4 of an online course on mathematical group theory. It introduces Lagrange's theorem that the order of a subgroup divides the order of a group, and uses it to show that all groups of prime order are cyclic, and to prove Fermat's theorem and Euler's theorem.
From playlist Group theory
The Hartman-Grobman Theorem, Structural Stability of Linearization, and Stable/Unstable Manifolds
This video explores a central result in dynamical systems: The Hartman-Grobman theorem. This theorem establishes when a fixed point of a nonlinear system will resemble its linearization. In particular, hyperbolic fixed points, where every eigenvalue has a non-zero real part, will be "str
From playlist Engineering Math: Differential Equations and Dynamical Systems
Visual Group Theory, Lecture 5.4: Fixed points and Cauchy's theorem
Visual Group Theory, Lecture 5.4: Fixed points and Cauchy's theorem We begin with a small lemma stating that if a group of prime order acts on a set S, then the number of fixed points is congruent to the size of the set, modulo p. We need this result to prove Cauchy's theorem, which says
From playlist Visual Group Theory
Act globally, compute...points and localization - Tara Holm
Tara Holm Cornell University; von Neumann Fellow, School of Mathematics October 20, 2014 Localization is a topological technique that allows us to make global equivariant computations in terms of local data at the fixed points. For example, we may compute a global integral by summing inte
From playlist Mathematics
Math 131 Fall 2018 100318 Heine Borel Theorem
Definition of limit point compactness. Compact implies limit point compact. A nested sequence of closed intervals has a nonempty intersection. k-cells are compact. Heine-Borel Theorem: in Euclidean space, compactness, limit point compactness, and being closed and bounded are equivalent
From playlist Course 7: (Rudin's) Principles of Mathematical Analysis (Fall 2018)