Urysohn's lemma

MAST30026 Lecture 22: Urysohn's lemma

I gave the proof of Urysohn's lemma and briefly elaborated some of its important consequences. Given a pair of closed disjoint subsets of a normal topological space, the lemma asserts the existence of a real-valued continuous function on the space which takes the value 0 on the first close

From playlist MAST30026 Metric and Hilbert spaces

RIngs 22 Hensel's lemma

This lecture is part of an online course on rings and modules. We continue the previous lecture on complete rings by discussing Hensel's lemma for finding roots of polynomials over p-adic rings or over power series rings. We sketch two proofs, by slowly improving a root one digit at a tim

From playlist Rings and modules

Urysohn widths mod p - Aleksandr Berdnikov

Short Talks by Postdoctoral Members Topic: Urysohn widths mod p Speaker: Aleksandr Berdnikov Affiliation: Member, School of Mathematics Date: September 20, 2022

From playlist Mathematics

Urysohn width - Alexey Balitskiy

Short Talks by Postdoctoral Members Topic: Urysohn width Speaker: Alexey Balitskiy Affiliation: Member, School of Mathematics Date: September 21, 2021

From playlist Mathematics

Theory of numbers: Gauss's lemma

This lecture is part of an online undergraduate course on the theory of numbers. We describe Gauss's lemma which gives a useful criterion for whether a number n is a quadratic residue of a prime p. We work it out explicitly for n = -1, 2 and 3, and as an application prove some cases of Di

From playlist Theory of numbers

Water and Wine

This course is on Lemma: http://lem.ma Lemma looking for developers: http://lem.ma/jobs Other than http://lem.ma, I recommend Strang http://bit.ly/StrangYT, Gelfand http://bit.ly/GelfandYT, and my short book of essays http://bit.ly/HALAYT Questions and comments below will be prompt

From playlist Problems, Paradoxes, and Sophisms

Franz Schuster: Blaschke–Santaló Inequalities for Minkowski and Asplund Endomorphisms

The Blaschke–Santaló inequality is one of the best known and most powerful affine isoperimetric inequalities in convex geometric analysis. In particular, it is significantly stronger than the classical Euclidean Urysohn inequality. In this talk, we present new isoperimetric inequalities fo

From playlist Workshop: High dimensional measures: geometric and probabilistic aspects

Linear Algebra 21g: Euler Angles and a Short Tribute to Leonhard Euler

https://bit.ly/PavelPatreon https://lem.ma/LA - Linear Algebra on Lemma http://bit.ly/ITCYTNew - Dr. Grinfeld's Tensor Calculus textbook https://lem.ma/prep - Complete SAT Math Prep

From playlist Part 3 Linear Algebra: Linear Transformations

Proof of Lemma and Lagrange's Theorem

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Proof of Lemma and Lagrange's Theorem. This video starts by proving that any two right cosets have the same cardinality. Then we prove Lagrange's Theorem which says that if H is a subgroup of a finite group G then the order of H div

From playlist Abstract Algebra

Commutative algebra 55: Dimension of local rings

This lecture is part of an online course on commutative algebra, following the book "Commutative algebra with a view toward algebraic geometry" by David Eisenbud. We give 4 definitions of the dimension of a Noetherian local ring: Brouwer-Menger-Urysohn dimension, Krull dimension, degree o

From playlist Commutative algebra

SEPARATION BUT MATHEMATICALLY: What Types of Mathematical Topologies are there? | Nathan Dalaklis

The title of this video is a bit convoluted. What do you mean by "Separation but Mathematically"? Well, in this video I'll be giving a (very diluted) answer to the question "What types of mathematical topologies are there?" by introducing the separation axioms in topology. The separation

From playlist The New CHALKboard

Zermelo Fraenkel Introduction

This lecture is part of an online course on the Zermelo Fraenkel axioms of set theory. This lecture gives an overview of the axioms, describes the von Neumann hierarchy, and sketches several approaches to interpreting the axioms (Platonism, von Neumann hierarchy, multiverse, formalism, pra

From playlist Zermelo Fraenkel axioms

The Straw Trick

This course is on Lemma: http://lem.ma Lemma looking for developers: http://lem.ma/jobs Other than http://lem.ma, I recommend Strang http://bit.ly/StrangYT, Gelfand http://bit.ly/GelfandYT, and my short book of essays http://bit.ly/HALAYT Questions and comments below will be prompt

From playlist Problems, Paradoxes, and Sophisms

The Campbell-Baker-Hausdorff and Dynkin formula and its finite nature

In this video explain, implement and numerically validate all the nice formulas popping up from math behind the theorem of Campbell, Baker, Hausdorff and Dynkin, usually a.k.a. Baker-Campbell-Hausdorff formula. Here's the TeX and python code: https://gist.github.com/Nikolaj-K/8e9a345e4c932

From playlist Algebra

Yevgeny Liokumovich (9/10/21): Urysohn width, isoperimetric inequalities and scalar curvature

There exists a positive constant c(n) with the following property. If M is a metric space, such that every ball B of radius 1 in M has Hausdorff n-dimensional measure less than c(n), then there exists a continuous map f from M to (n-1)-dimensional simplicial complex, such that every pre-im

From playlist Vietoris-Rips Seminar

Graph regularity and counting lemmas - Jacob Fox

Conference on Graphs and Analysis Jacob Fox June 5, 2012 More videos on http://video.ias.edu

From playlist Mathematics

Regularity methods in combinatorics, number theory, and computer science - Jacob Fox

Marston Morse Lectures Topic: Regularity methods in combinatorics, number theory, and computer science Speaker: Jacob Fox Affiliation: Stanford University Date: October 24, 2016 For more videos, visit http://video.ias.edu

From playlist Mathematics

9. Szemerédi's graph regularity lemma IV: induced removal lemma

MIT 18.217 Graph Theory and Additive Combinatorics, Fall 2019 Instructor: Yufei Zhao View the complete course: https://ocw.mit.edu/18-217F19 YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP62qauV_CpT1zKaGG_Vj5igX Prof. Zhao explains a strengthening of the graph regulari

From playlist MIT 18.217 Graph Theory and Additive Combinatorics, Fall 2019

Commutative algebra 51: Hensel's lemma continued

This lecture is part of an online course on commutative algebra, following the book "Commutative algebra with a view toward algebraic geometry" by David Eisenbud. This lecture continues the discussion of Hensel's lemma. We first use it to find the structure of the group of units of the p-

From playlist Commutative algebra