invariant
property of mathematical objects that remains unchanged for transformations applied to the objects
charge-parity-time symmetry
physics theorem
graph property
isomorphism-invariant property of graphs
length
integer invariant of a module in linear algebra
systole
minimum length of a noncontractible closed curve in a metric space
covering number
number of balls of a given size needed to cover a given space
order of a group element
smallest positive integer such that, when used as exponent of the subject element, gives the group identity element
rank
measure of the "nondegenerateness" of the system of linear equations and linear transformation encoded by a matrix
characteristic
in a field or a ring, the smallest positive integer, if any, such that the sum of n ones equals 0; zero otherwise
signature
number of positive, negative and zero eigenvalues of a metric tensor
Homology
general way of associating a sequence of algebraic objects to other mathematical objects
discriminant of an algebraic number field
invariant that measures the size of the ring of integers of the algebraic number field
module of an automorphism
invariant of automorphism with respect ot Haar measure
Chow ring
Analogs of homology groups for algebraic varieties
self-linking number
invariant of framed knots
Dehn invariant
Parameter of a polyhedron
winding number
number of times a curve wraps around a point in the plane
degree of a polynomial
highest power of the variables occurring in a monomial in a given polynomial
invariant polynomial
polynomial invariant under a group action
dimension
maximum number of independent directions within a mathematical space
eta invariant
Differential operator
topological property
object of study in the category of topological spaces
writhe of a link diagram
invariant of a knot diagram, but not of knots
Krull dimension
Algebraic definition of the dimension of a ring
transcendence degree
measure of the "size" of a field extension
Modular invariant theory
sub-field of mathematics
similarity invariance
property of a function whose value is unchanged by change of basis
real rank
integer-valued invariant of C*-algebras
Lebesgue covering dimension
invariant associated to a topological space; the smallest integer 𝑛 such that, for every cover, there is a refinement in which every point lies in the intersection of at most 𝑛+1 covering sets
inductive dimension
topologically invariant definition of the dimension of a space
constant
in computer programming, a value that should not or cannot be altered by the program during normal execution
invariant
in mathematics and theoretical physics, property of a system which remains unchanged under some transformation
rank of a Lie algebra
dimension of any Cartan subalgebra of specified Lie algebra
fixed-point property
mathematical property
fundamental discriminant
integer invariant of integral binary quadratic forms, associating the integer 𝑏²−4𝑎𝑐 to the quadratic form 𝑎𝑥²+𝑏𝑥𝑦+𝑐𝑦²
Hilbert polynomial
polynomial function with rational coefficients whose values agree, for sufficiently large argument, with the dimensions of graded components of a graded algebra
Hopf invariant
Homotopy invariant of maps between spheres
major index
mathematical measure of a permutation, in combinatorics