User:Richard Pinch/Articles
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Absorbing element: An element whose behaviour with respect to an algebraic binary operation is like that of zero with respect to multiplication. [e]
- Albert algebra: An exceptional Jordan algebra, consisting of 3×3 self-adjoint matrices over the octonions. [e]
Algebra over a field: A ring containing an isomorphic copy of a given field in its centre. [e]
Algebraic independence: The property of elements of an extension field which satisfy only the trivial polynomial relation. [e]
Alternant code: A class of parameterised error-correcting codes which generalise the BCH codes. [e]
Altitude (geometry): In a triangle, a line from a vertex perpendicular to the opposite side. [e]
Arithmetic function: A function defined on the set of positive integers, usually with integer, real or complex values, studied in number theory. [e]
Artin-Schreier polynomial: A type of polynomial whose roots generate extensions of degree p in characteristic p. [e]
Associativity: A property of an algebraic operation such as multiplication: a(bc) = (ab)c. [e]
Automorphism: An isomorphism of an algebraic structure with itself: a permutation of the underlying set which respects all algebraic operations. [e]
Average order of an arithmetic function: A simple or well-known function, usually continuous and montonic, which on average takes the same or closely approximate values as a given arithmetic function. [e]
Baer-Specker group: An example of an infinite Abelian group which is a building block in the structure theory of such groups. [e]
Barycentre: The centre of mass of a body or system of particles, a weighted average where certain forces may be taken to act. [e]
Barycentric coordinates: The weights that would have to be assigned to a system of reference points to yield a given position as barycentre are used as coordinates. [e]
Binary operation: A function of two elements within a set, which assigns another value from among the elements of the set. [e]
Brun-Titchmarsh theorem: An upper bound on the distribution on primes in an arithmetic progression. [e]
Cameron-Erdos conjecture: Add brief definition or description
Cartesian product: The set of ordered pairs whose elements come from two given sets. [e]
Centraliser: The set of all group elements which commute with every element of a given subset. [e]
Centre of a group: The subgroup of a group consisting of all elements which commute with every element of the group. [e]
Centre of a ring: The subring of a ring consisting of all elements which commute with every element of the ring. [e]
Cevian line: A line from the vertex of a triangle to some point on the opposite edge. [e]
Chain rule: A rule in calculus for differentiating a function of a function. [e]
Characteristic function: A function on a set which takes the value 1 on a given subset and 0 on its complement. [e]
Characteristic polynomial: The polynomial attached to a square matrix or endomorphism det(A-XI)=0. [e]
- Circumcentre: The centre of the circle that goes through the vertices of a triangle or a cyclic polygon. [e]
Closure operator: An idempotent unary operator on subsets of a given set, mapping a set to a larger set with a particular property. [e]
Cocountable topology: The topology on a space in which the open sets are those with countable complements, or the empty set. [e]
Cofactor (mathematics): A component of a matrix computation of the determinant; a signed determinant of a matrix minor. [e]
Cofinite topology: The topology on a space in which the open sets are those with finite complement, or the empty set. [e]
Commutativity: A property of a binary operation (such as addition or multiplication), that the two operands may be interchanged without affecting the result. [e]
Commutator: A measure of how close two elements of a group are to commuting. [e]
Compactification: A compact space in which a given topological space can be embedded as a dense subset. [e]
Compactness axioms: Properties of a toplogical space related to compactness. [e]
Complement (linear algebra): A pair of subspaces which form an (internal) direct sum. [e]
Complement (set theory): The set containing those elements of a set (or "universal" set) which are not contained in a given set. [e]
Complex conjugation: The operation on complex numbers which changes the sign of the imaginary part, x+iy → x-iy [e]
Conductor of an abelian variety: A measure of the nature of the bad reduction at some prime. [e]
Congruent triangles: In Euclidean geometry, triangles which can be superposed by a rigid motion. [e]
Conjugation (group theory): The elements of any group that may be partitioned into conjugacy classes. [e]
Connected space: A topological space in which there is no non-trivial subset which is both open and closed. [e]
Content (algebra): The highest common factor of the coefficients of a polynomial. [e]
Continuant (mathematics): An algebraic expression which has applications in generalized continued fractions and as the determinant of a tridiagonal matrix. [e]
- Convolution: Add brief definition or description
Coprime: Integers, or more generally elements of a ring, which have no non-trivial common factor. [e]
Countability axioms in topology: Properties that a topological space may satisfy which refer to the countability of certain structures within the space. [e]
Cubic reciprocity: Various results connecting the solvability of two related cubic equations in modular arithmetic, generalising the concept of quadratic reciprocity. [e]
Cyclic group: Add brief definition or description
Cyclic polygon: Add brief definition or description
Cyclotomic field: Add brief definition or description
Cyclotomic polynomial: Add brief definition or description
Delta form: Add brief definition or description
Derivation (mathematics): Add brief definition or description
Diagonal matrix: Add brief definition or description
Different ideal: Add brief definition or description
Differential ring: Add brief definition or description
Dirichlet series: Add brief definition or description
Discrete metric: Add brief definition or description
Discrete space: Add brief definition or description
Discriminant of a polynomial: Add brief definition or description
Discriminant of an algebraic number field: Add brief definition or description
Disjoint union: Add brief definition or description
Distributivity: Add brief definition or description
Division (arithmetic): Add brief definition or description
Division ring: Add brief definition or description
Divisor (algebraic geometry): Add brief definition or description
Door space: Add brief definition or description
Dowker space: Add brief definition or description
- Empty set: Add brief definition or description
End (topology): Add brief definition or description
- Equivalence relation: Add brief definition or description
Erdos-Fuchs theorem: Add brief definition or description
Error function: Add brief definition or description
Essential subgroup: Add brief definition or description
Exact sequence: Add brief definition or description
- Factorial: Add brief definition or description
Field automorphism: Add brief definition or description
Filter (mathematics): Add brief definition or description
Frattini subgroup: Add brief definition or description
Free group: Add brief definition or description
Frobenius map: Add brief definition or description
Function composition: Add brief definition or description
Functional equation: Add brief definition or description
Generic point: Add brief definition or description
Genus field: Add brief definition or description
Group action: Add brief definition or description
Group homomorphism: Add brief definition or description
Group isomorphism problem: Add brief definition or description
Hall polynomial: Add brief definition or description
Hall-Littlewood polynomial: Add brief definition or description
Heine–Borel theorem: Add brief definition or description
Hutchinson operator: Add brief definition or description
Idempotence: Add brief definition or description
Idempotent element: Add brief definition or description
Identity element: Add brief definition or description
Identity function: Add brief definition or description
Identity matrix: Add brief definition or description
Incentre: Add brief definition or description
Injective function: Add brief definition or description
Interior (topology): Add brief definition or description
Intersection: Add brief definition or description
Isolated singularity: Add brief definition or description
Jordan's totient function: Add brief definition or description
Justesen code: Add brief definition or description
KANT: Add brief definition or description
Kernel of a function: Add brief definition or description
Kronecker delta: Add brief definition or description
Krull dimension: Add brief definition or description
Lambda function: Add brief definition or description
Lattice (geometry): Add brief definition or description
Limit point: Add brief definition or description
Littlewood polynomial: Add brief definition or description
Manin obstruction: Add brief definition or description
Median algebra: Add brief definition or description
Minimal polynomial: Add brief definition or description
Möbius function: Add brief definition or description
Modulus (algebraic number theory): Add brief definition or description
Monogenic field: Add brief definition or description
Monoid: Add brief definition or description
Monotonic function: Add brief definition or description
Moore determinant: Add brief definition or description
Morita conjectures: Add brief definition or description
Neighbourhood: Add brief definition or description
- Nine-point centre: Add brief definition or description
Noetherian module: Add brief definition or description
Normal extension: Add brief definition or description
Normal number: Add brief definition or description
Normal order of an arithmetic function: Add brief definition or description
Normaliser: Add brief definition or description
Nowhere dense set: Add brief definition or description
- Null set: Add brief definition or description
Number of divisors function: Add brief definition or description
Number Theory Foundation: Add brief definition or description
Order (group theory): Add brief definition or description
Order (relation): Add brief definition or description
Ordered field: Add brief definition or description
Ordered pair: Add brief definition or description
p-adic metric: Add brief definition or description
Partition (mathematics): Add brief definition or description
Partition function (number theory): Add brief definition or description
Pedal triangle: Add brief definition or description
Pointwise operation: Add brief definition or description
Pole (complex analysis): Add brief definition or description
Power set: Add brief definition or description
Preparata code: Add brief definition or description
Primitive root: Add brief definition or description
Product topology: Add brief definition or description
Quadratic field: Add brief definition or description
Quadratic residue: Add brief definition or description
Quotient topology: Add brief definition or description
Relation (mathematics): Add brief definition or description
Relation composition: Add brief definition or description
Removable singularity: Add brief definition or description
Residual property (mathematics): Add brief definition or description
Resolution (algebra): Add brief definition or description
Resultant (algebra): Add brief definition or description
Resultant (statics): Add brief definition or description
Rigid motion: Add brief definition or description
Ring homomorphism: Add brief definition or description
Root of unity: Add brief definition or description
S-unit: Add brief definition or description
Selberg sieve: Add brief definition or description
Semigroup: Add brief definition or description
Separation axioms: Add brief definition or description
Series (group theory): Add brief definition or description
Singleton set: Add brief definition or description
Sober space: Add brief definition or description
Srivastava code: Add brief definition or description
Stably free module: Add brief definition or description
Stirling number: Add brief definition or description
Subgroup: Add brief definition or description
Subspace topology: Add brief definition or description
Sum-of-divisors function: Add brief definition or description
Surjective function: Add brief definition or description
Sylow subgroup: Add brief definition or description
Symmetric difference: Add brief definition or description
Szpiro's conjecture: Add brief definition or description
Tau function: Add brief definition or description
Theta function: Add brief definition or description
Totient function: Add brief definition or description
Transitive relation: Add brief definition or description
Turan sieve: Add brief definition or description
Tutte matrix: Add brief definition or description
Weierstrass preparation theorem: Add brief definition or description
Zero matrix: Add brief definition or description
Zipf distribution: Add brief definition or description