Algebraic properties of elements | Ring theory | Group theory | Algebraic number theory

Unit (ring theory)

In algebra, a unit of a ring is an invertible element for the multiplication of the ring. That is, an element u of a ring R is a unit if there exists v in R such that where 1 is the multiplicative identity; the element v is unique for this property and is called the multiplicative inverse of u. The set of units of R forms a group R× under multiplication, called the group of units or unit group of R. Other notations for the unit group are R∗, U(R), and E(R) (from the German term Einheit). Less commonly, the term unit is sometimes used to refer to the element 1 of the ring, in expressions like ring with a unit or unit ring, and also unit matrix. Because of this ambiguity, 1 is more commonly called the "unity" or the "identity" of the ring, and the phrases "ring with unity" or a "ring with identity" may be used to emphasize that one is considering a ring instead of a rng. (Wikipedia).

Video thumbnail

Units in a Ring (Abstract Algebra)

The units in a ring are those elements which have an inverse under multiplication. They form a group, and this “group of units” is very important in algebraic number theory. Using units you can also define the idea of an “associate” which lets you generalize the fundamental theorem of ar

From playlist Abstract Algebra

Video thumbnail

RNT1.1. Definition of Ring

Ring Theory: We define rings and give many examples. Items under consideration include commutativity and multiplicative inverses. Example include modular integers, square matrices, polynomial rings, quaternions, and adjoins of algebraic and transcendental numbers.

From playlist Abstract Algebra

Video thumbnail

RNT1.4. Ideals and Quotient Rings

Ring Theory: We define ideals in rings as an analogue of normal subgroups in group theory. We give a correspondence between (two-sided) ideals and kernels of homomorphisms using quotient rings. We also state the First Isomorphism Theorem for Rings and give examples.

From playlist Abstract Algebra

Video thumbnail

Definition of a Ring and Examples of Rings

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Definition of a Ring and Examples of Rings - Definition of a Ring. - Definition of a commutative ring and a ring with identity. - Examples of Rings include: Z, Q, R, C under regular addition and multiplication The Ring of all n x

From playlist Abstract Algebra

Video thumbnail

Visual Group Theory, Lecture 7.1: Basic ring theory

Visual Group Theory, Lecture 7.1: Basic ring theory A ring is an abelian group (R,+) with a second binary operation, multiplication and the distributive law. Multiplication need not commute, nor need there be multiplicative inverses, so a ring is like a field but without these properties.

From playlist Visual Group Theory

Video thumbnail

Abstract Algebra | What is a ring?

We give the definition of a ring and present some examples. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/

From playlist Abstract Algebra

Video thumbnail

Abstract Algebra: The definition of a Ring

Learn the definition of a ring, one of the central objects in abstract algebra. We give several examples to illustrate this concept including matrices and polynomials. Be sure to subscribe so you don't miss new lessons from Socratica: http://bit.ly/1ixuu9W ♦♦♦♦♦♦♦♦♦♦ We recommend th

From playlist Abstract Algebra

Video thumbnail

Rings and modules 2: Group rings

This lecture is part of an online course on rings and modules. We decribe some examples of rings constructed from groups and monoids, such as group rings and rings of Dirichlet polynomials. For the other lectures in the course see https://www.youtube.com/playlist?list=PL8yHsr3EFj52XDLrm

From playlist Rings and modules

Video thumbnail

RNT1.3. Ring Homomorphisms

Ring Theory: We define ring homomorphisms, ring isomorphisms, and kernels. These will be used to draw an analogue to the connections in group theory between group homomorphisms, normal subgroups, and quotient groups.

From playlist Abstract Algebra

Video thumbnail

Structure of group rings and the group of units of integral group rings (Lecture 1) by Eric Jespers

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 fun

From playlist Group Algebras, Representations And Computation

Video thumbnail

Arthur Bartels: K-theory of group rings (Lecture 1)

The lecture was held within the framework of the Hausdorff Trimester Program: K-Theory and Related Fields. Arthur Bartels: K-theory of group rings The Farrell-Jones Conjecture predicts that the K-theory of group rings RG can be computed in terms of K-theory of group rings RV where V vari

From playlist HIM Lectures: Trimester Program "K-Theory and Related Fields"

Video thumbnail

Visual Group Theory: Lecture 7.4: Divisibility and factorization

Visual Group Theory: Lecture 7.4: Divisibility and factorization The ring of integers have a number of properties that we take for granted: every number can be factored uniquely into primes, and all pairs of numbers have a unique gcd and lcm. In this lecture, we investigate when this happ

From playlist Visual Group Theory

Video thumbnail

Haldun Özgür Bayindir : Adjoining roots to ring spectra and algebraic 𝐾-theory

CONFERENCE Recording during the thematic meeting : « Chromatic Homotopy, K-Theory and Functors» the January 24, 2023 at the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Jean Petit Find this video and other talks given by worldwide mathematicians on CIR

From playlist Topology

Video thumbnail

On the pioneering works of Professor I.B.S. Passi by Sugandha Maheshwari

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

Video thumbnail

Benjamin Steinberg: Cartan pairs of algebras

Talk by Benjamin Steinberg in Global Noncommutative Geometry Seminar (Americas), https://globalncgseminar.org/talks/tba-15/ on Oct. 8, 2021

From playlist Global Noncommutative Geometry Seminar (Americas)

Video thumbnail

Giles Gardam - Kaplansky's conjectures

Kaplansky made various related conjectures about group rings, especially for torsion-free groups. For example, the zero divisors conjecture predicts that if K is a field and G is a torsion-free group, then the group ring K[G] has no zero divisors. I will survey what is known about the conj

From playlist Talks of Mathematics Münster's reseachers

Video thumbnail

Lars Hesselholt: The big de Rham Witt complex

The lecture was held within the framework of the Hausdorff Trimester Program: Non-commutative Geometry and its Applications and the Workshop: Number theory and non-commutative geometry 26.11.2014

From playlist HIM Lectures: Trimester Program "Non-commutative Geometry and its Applications"

Video thumbnail

Perfectoid spaces (Lecture 2) by Kiran Kedlaya

PERFECTOID SPACES ORGANIZERS: Debargha Banerjee, Denis Benois, Chitrabhanu Chaudhuri, and Narasimha Kumar Cheraku DATE & TIME: 09 September 2019 to 20 September 2019 VENUE: Madhava Lecture Hall, ICTS, Bangalore Scientific committee: Jacques Tilouine (University of Paris, France) Eknath

From playlist Perfectoid Spaces 2019

Video thumbnail

RNT2.4. Gaussian Primes

Ring Theory: As an application of all previous ideas on rings, we determine the primes in the Euclidean domain of Gaussian integers Z[i]. Not only is the answer somewhat elegant, but it contains a beautiful theorem on prime integers due to Fermat. We finish with examples of factorization

From playlist Abstract Algebra

Related pages

Quadratic integer | Integral domain | Finite field | Division ring | Zero ring | Maximal ideal | Hua's identity | Ring of integers | Dirichlet's unit theorem | Group (mathematics) | Root of unity | Nilpotent | Multiplicative group of integers modulo n | Additive identity | Rng (algebra) | Determinant | Additive inverse | Algebra | André Weil | Polynomial ring | Semigroup | General linear group | Group ring | Adjugate matrix | Field (mathematics) | Ring homomorphism | Square matrix | Real number | Group scheme | Cyclic group | Ring (mathematics) | Number theory | Functor | Equivalence relation | Local ring | Group homomorphism | Category of rings | Category of groups | Domain (ring theory) | Cardinality | Green's relations | Modular arithmetic | Invertible matrix | Multiplicative inverse | Commutative ring