Set theory

Jensen's covering theorem

In set theory, Jensen's covering theorem states that if 0# does not exist then every uncountable set of ordinals is contained in a constructible set of the same cardinality. Informally this conclusion says that the constructible universe is close to the universe of all sets. The first proof appeared in. Silver later gave a fine structure free proof using his machines and finally Magidor gave an even simpler proof. The converse of Jensen's covering theorem is also true: if 0# exists then the countable set of all cardinals less than ℵω cannot be covered by a constructible set of cardinality less than ℵω. In his book Proper Forcing, Shelah proved a strong form of Jensen's covering lemma. (Wikipedia).

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Universal covering spaces | Algebraic Topology | NJ Wildberger

We begin by giving some examples of the main theorem from the last lecture: that the associated homomorphism of fundamental groups associated to a covering space p:X to B injects pi(X) as a subgroup of pi(B). We look at helical coverings of a circle, and also a two-fold covering of the wed

From playlist Algebraic Topology

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Lie groups: Poincare-Birkhoff-Witt theorem

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From playlist Lie groups

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AlgTop28: Covering spaces and fundamental groups

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From playlist Algebraic Topology

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Functional Analysis Lecture 13 2014 03 061 Boundedness of Hilbert Transform on Hardy Space (part 2)

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From playlist Course 9: Basic Functional and Harmonic Analysis

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Functional Analysis Lecture 12 2014 03 04 Boundedness of Hilbert Transform on Hardy Space (part 1)

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From playlist Course 9: Basic Functional and Harmonic Analysis

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From playlist Course 9: Basic Functional and Harmonic Analysis

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What is Stokes theorem? - Formula and examples

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From playlist Vectors

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Assaf Rinot : Distributive Aronszajn trees

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From playlist Logic and Foundations

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Vertex Covering Number of Complete Graphs | Graph Theory Exercises

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From playlist Graph Theory Exercises

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Lectures on compactness in the ̄∂–Neumann problem (Lecture 4) by Emil Straube

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From playlist Cauchy-Riemann Equations in Higher Dimensions 2019

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Thm 1.10 - Probabilistic Version - part 06 - "Second Term"

Here we apply Jensen's inquality.

From playlist Theorem 1.10

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Lectures on compactness in the ̄∂–Neumann problem (Lecture 5) by Emil Straube

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From playlist Cauchy-Riemann Equations in Higher Dimensions 2019

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Hannah Larson - A refined Brill-Noether theory over Hurwitz spaces - AGONIZE miniconference

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From playlist Arithmetic Geometry is ONline In Zoom, Everyone (AGONIZE)

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Thorben Kastenholz: Simplicial Volume of Total Spaces of Fiber Bundles

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From playlist 39th Annual Geometric Topology Workshop (Online), June 6-8, 2022

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Matthew Kennedy: Noncommutative convexity

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From playlist Global Noncommutative Geometry Seminar (Europe)

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From playlist Number Theory Research Unit at CAMS - AUB

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Quenched large deviations for random motions in degenerate random media by Chiranjib Mukherjeer

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From playlist Large deviation theory in statistical physics: Recent advances and future challenges

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Surface groups are flexibly stable - Nir Lazarovich

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From playlist Stability and Testability

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Lie Groups and Lie Algebras: Lesson 41: Elementary Representation Theory I

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From playlist Lie Groups and Lie Algebras

Related pages

Set theory | Zero sharp | Constructible universe | Silver machine