A cyclic number is a natural number n such that n and φ(n) are coprime. Here φ is Euler's totient function. An equivalent definition is that a number n is cyclic if and only if any group of order n is cyclic. Any prime number is clearly cyclic. All cyclic numbers are square-free.Let n = p1 p2 … pk where the pi are distinct primes, then φ(n) = (p1 − 1)(p2 − 1)...(pk – 1). If no pi divides any (pj – 1), then n and φ(n) have no common (prime) divisor, and n is cyclic. The first cyclic numbers are 1, 2, 3, 5, 7, 11, 13, 15, 17, 19, 23, 29, 31, 33, 35, 37, 41, 43, 47, 51, 53, 59, 61, 65, 67, 69, 71, 73, 77, 79, 83, 85, 87, 89, 91, 95, 97, 101, 103, 107, 109, 113, 115, 119, 123, 127, 131, 133, 137, 139, 141, 143, 145, 149, ... (sequence in the OEIS). (Wikipedia).
Cyclic groups and finite groups
Jacob goes into detail on some particularly important finite groups, and explains how groups and subgroups can be generated by their elements, along with some important consequences.
From playlist Basics: Group Theory
Abstract Algebra | Subgroups of Cyclic Groups
We prove that all subgroups of cyclic groups are themselves cyclic. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/
From playlist Abstract Algebra
Definition of a Cyclic Group with Examples
Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Definition of a Cyclic Group with Examples
From playlist Abstract Algebra
Group theory 16: Automorphisms of cyclic groups
This lecture is part of an online mathematics course on group theory. It is mostly about the structure of the group of automorphisms of a cyclic group. As an application we classify the groups of order pq for primes p, q.
From playlist Group theory
Cyclic Groups, Generators, and Cyclic Subgroups | Abstract Algebra
We introduce cyclic groups, generators of cyclic groups, and cyclic subgroups. We discuss an isomorphism from finite cyclic groups to the integers mod n, as well as an isomorphism from infinite cyclic groups to the integers. We establish a cyclic group of order n is isomorphic to Zn, and a
From playlist Abstract Algebra
Abstract Algebra | Cyclic Subgroups
We define the notion of a cyclic subgroup and give a few examples. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/
From playlist Abstract Algebra
Group theory 15:Groups of order 12
This lecture is part of an online mathematics course on group theory. It uses the Sylow theorems to classify the groups of order 12, and finds their subgroups.
From playlist Group theory
This is lecture 5 of an online mathematics course on group theory. It classifies groups of order 4 and gives several examples of products of groups.
From playlist Group theory
Visual Group Theory, Lecture 2.1: Cyclic and abelian groups
Visual Group Theory, Lecture 2.1: Cyclic and abelian groups In this lecture, we introduce two important families of groups: (1) "cyclic groups", which are those that can be generated by a single element, and (2) "abelian groups", which are those for which multiplication commutes. Addition
From playlist Visual Group Theory
Teena Gerhardt - 1/3 Algebraic K-theory and Trace Methods
Algebraic K-theory is an invariant of rings and ring spectra which illustrates a fascinating interplay between algebra and topology. Defined using topological tools, this invariant has important applications to algebraic geometry, number theory, and geometric topology. One fruitful approac
From playlist Summer School 2020: Motivic, Equivariant and Non-commutative Homotopy Theory
Paolo Piazza: Proper actions of Lie groups and numeric invariants of Dirac operators
HYBRID EVENT shall explain how to define and investigate primary and secondary invariants of G-invariant Dirac operators on a cocompact G-proper manifold, with G a connected real reductive Lie group. This involves cyclic cohomology and Ktheory. After treating the case of cyclic cocycles a
From playlist Lie Theory and Generalizations
Yanli Song: Higher index theorem for proper actions of Lie groups
Talk by Yanli Song in Global Noncommutative Geometry Seminar (Americas) http://www.math.wustl.edu/~xtang/NCG-Seminar.html on May 6, 2020.
From playlist Global Noncommutative Geometry Seminar (Americas)
Primitive roots modulo n and the structure of U(n)
We review the definition of a primitive root modulo n and apply it to determining the structure of U(n), the group of units modulo n. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/
From playlist Abstract Algebra
Introduction to number theory lecture 28. Products of groups
This lecture is part of my Berkeley math 115 course "Introduction to number theory" For the other lectures in the course see https://www.youtube.com/playlist?list=PL8yHsr3EFj53L8sMbzIhhXSAOpuZ1Fov8 We define products of groups, and rephrase some earlier results in terms of these products.
From playlist Introduction to number theory (Berkeley Math 115)
Visual Group Theory, Lecture 4.4: Finitely generated abelian groups
Visual Group Theory, Lecture 4.4: Finitely generated abelian groups We begin this lecture by proving that the cyclic group of order n*m is isomorphic to the direct product of cyclic groups of order n and m if and only if gcd(n,m)=1. Then, we classify all finite abelian groups by decomposi
From playlist Visual Group Theory
Kevin Buzzard (lecture 3/20) Automorphic Forms And The Langlands Program [2017]
Full course playlist: https://www.youtube.com/playlist?list=PLhsb6tmzSpiysoRR0bZozub-MM0k3mdFR http://wwwf.imperial.ac.uk/~buzzard/MSRI/ Summer Graduate School Automorphic Forms and the Langlands Program July 24, 2017 - August 04, 2017 Kevin Buzzard (Imperial College, London) https://w
From playlist MSRI Summer School: Automorphic Forms And The Langlands Program, by Kevin Buzzard [2017]
Cyclic Groups (Abstract Algebra)
Cyclic groups are the building blocks of abelian groups. There are finite and infinite cyclic groups. In this video we will define cyclic groups, give a list of all cyclic groups, talk about the name “cyclic,” and see why they are so essential in abstract algebra. Be sure to subscribe s
From playlist Abstract Algebra
Crossed Products and Coding Theory by Yuval Ginosar
PROGRAM GROUP ALGEBRAS, REPRESENTATIONS AND COMPUTATION ORGANIZERS: Gurmeet Kaur Bakshi, Manoj Kumar and Pooja Singla DATE: 14 October 2019 to 23 October 2019 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Determining explicit algebraic structures of semisimple group algebras is a fund
From playlist Group Algebras, Representations And Computation