Congruence

Congruence may refer to:

Mathematics

Congruence (geometry), being roughly, the same size and shape
Congruence or congruence relation, in abstract algebra, an equivalence relation on an algebraic structure that is compatible with the structure
In modular arithmetic, having the same remainder when divided by a specified integer
- Ramanujan's congruences, congruences for the partition function, $p (n)$ , first discovered by Ramanujan in 1919
- Congruence subgroup, a subgroup defined by congruence conditions on the entries of a matrix group with integer entries
- Congruence of squares, in number theory, a congruence commonly used in integer factorization algorithms
Matrix congruence, an equivalence relation between two matrices.
Congruence (manifolds), in the theory of smooth manifolds, the set of integral curves defined by a nonvanishing vector field defined on the manifold
Congruence (general relativity), in general relativity, a congruence in a four-dimensional Lorentzian manifold that is interpreted physically as a model of space time, or a bundle of world lines
Zeller's congruence, an algorithm to calculate the day of the week for any date
Scissors congruence, related to Hilbert's third problem

In Carl Rogers' personality theory, the compliance between ideal self and actual self-see Carl Rogers#Incongruence
Mood congruence between feeling or emotion (in psychiatry and psychology)
Incongruity theory of humor