Ordinal numbers | Cardinal numbers
The von Neumann cardinal assignment is a cardinal assignment that uses ordinal numbers. For a well-orderable set U, we define its cardinal number to be the smallest ordinal number equinumerous to U, using the von Neumann definition of an ordinal number. More precisely: where ON is the class of ordinals. This ordinal is also called the initial ordinal of the cardinal. That such an ordinal exists and is unique is guaranteed by the fact that U is well-orderable and that the class of ordinals is well-ordered, using the axiom of replacement. With the full axiom of choice, every set is well-orderable, so every set has a cardinal; we order the cardinals using the inherited ordering from the ordinal numbers. This is readily found to coincide with the ordering via ≤c. This is a well-ordering of cardinal numbers. (Wikipedia).
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
Maurice Herlihy: Applying Combinatorial Topology to Byzantine Tasks
The lecture was held within the framework of the Hausdorff Trimester Program : Applied and Computational Algebraic Topology
From playlist HIM Lectures: Special Program "Applied and Computational Algebraic Topology"
The Mind of a Genius: John von Neumann I The Great Courses
If John von Neumann were on LinkedIn, his experience would include the Manhattan Project, early computer science, the atomic bomb, the hydrogen bomb, and the invention of game theory. A famed mathematician, Neumann played a major role in all of these by using applied heuristics. Add heuris
From playlist Science
BM9.1. Cardinality 1: Finite Sets
Basic Methods: We define cardinality as an equivalence relation on sets using one-one correspondences. In this talk, we consider finite sets and counting rules.
From playlist Math Major Basics
Zermelo Fraenkel Pairing and union
This is part of a series of lectures on the Zermelo-Fraenkel axioms for set theory. We discuss the axioms of pairing and union, the two easiest axioms of ZFC, and consider whether they are really needed. For the other lectures in the course see https://www.youtube.com/playlist?list=PL
From playlist Zermelo Fraenkel axioms
This is part of a series of lectures on the Zermelo-Fraenkel axioms for set theory. We discuss the powerset axiom, the strongest of the ZF axioms, and explain why the notion of a powerset is so hard to pin down precisely. For the other lectures in the course see https://www.youtube.com
From playlist Zermelo Fraenkel axioms
32: What is Life? The Amazing R.H. Conway - Richard Buckland UNSW
This is an extension lecture for interested students - nothing examinable, it's just for fun. Lecture 32 "Computing 2" Comp1927 (This upload attempts to fix the audio sync problem in my first attempt.)
From playlist CS2: Data Structures and Algorithms - Richard Buckland
Defining Infinity | Infinite Series
Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi Set theory is supposed to be a foundation of all of mathematics. How does it handle infinity? Learn through active problem-solving at Brilliant: https://brilliant.org/I
From playlist An Infinite Playlist
Sergey Neshveyev: Drinfeld center, tube algebra, and representation theory of monoidal categories
Sergey Neshveyev: Drinfeld center, tube algebra, and representation theory of monoidal categories Abstract: I will review and clarify the connections between several constructions in category theory, subfactor theory and quantum groups, such as Drinfeld center, Drinfeld double, Ocneanu's
From playlist HIM Lectures: Trimester Program "Von Neumann Algebras"
Shmuel Weinberger: Descriptive geometry of function spaces
The lecture was held within the framework of the Hausdorff Trimester Program : Applied and Computational Algebraic Topology
From playlist HIM Lectures: Special Program "Applied and Computational Algebraic Topology"
Lauren Ruth: "Von Neumann Equivalence"
Actions of Tensor Categories on C*-algebras 2021 "Von Neumann Equivalence" Lauren Ruth - Mercy College, Mathematics Abstract: We introduce a new equivalence relation on groups, which we call von Neumann equivalence, that is coarser than both measure equivalence and W*-equivalence. Our ge
From playlist Actions of Tensor Categories on C*-algebras 2021
The Mathematical Infinity - Enrico Bombieri
This lecture by [Enrico Bombieri](http://www.ias.edu/people/faculty-and-emeriti/bombieri), IBM von Neumann Professor in the School of Mathematics, explores how mathematics has arrived at its present pragmatic view of infinity and some of the counterintuitive paradoxes, as well as some of t
From playlist Mathematics
Should the power class of any non-empty set even be a set? It's not in constructive Zermelo-Fraenkel, but once you add the Axiom of Choice you end up in ZFC where you have to assign it a cardinal number. But then, well-orderings on something like the reals provably exist that are not descr
From playlist Logic
Rolando de Santiago: "L2 cohomology and maximal rigid subalgebras of s-malleable deformations"
Actions of Tensor Categories on C*-algebras 2021 "L2 cohomology and maximal rigid subalgebras of s-malleable deformations" Rolando de Santiago - Purdue University, Department of Mathematics Abstract: A major theme in the study of von Neumann algebras is to investigate which structural as
From playlist Actions of Tensor Categories on C*-algebras 2021
Introduction to the Cardinality of Sets and a Countability Proof
Introduction to Cardinality, Finite Sets, Infinite Sets, Countable Sets, and a Countability Proof - Definition of Cardinality. Two sets A, B have the same cardinality if there is a bijection between them. - Definition of finite and infinite sets. - Definition of a cardinal number. - Discu
From playlist Set Theory
U. Brehm: A Universality Theorem for Realization Spaces of Polyhedral Maps
U. Brehms lecture was held within the framework of the Hausdorff Trimester Program Universality and Homogeneity during the special seminar "Universality of moduli spaces and geometry" (06.11.2013) Due to an error with the recording, there is no video available for this lecture.
From playlist HIM Lectures: Trimester Program "Universality and Homogeneity"
8ECM Invited Lecture: Mirjam Dür
From playlist 8ECM Invited Lectures
Steven Charlton: Bowman Bradley type relations for symmetrized multiple zeta values
The lecture was held within the framework of the Hausdorff Trimester Program: Periods in Number Theory, Algebraic Geometry and Physics.
From playlist HIM Lectures: Trimester Program "Periods in Number Theory, Algebraic Geometry and Physics"