A collection of humans or animals who share certain characteristics, interact with one another, accept expectations and obligations as members of the group, and share a common identity.

An algebraist who specializes in group theory

plural of group theorist

(mathematics) A group such that every injective cellular automaton with the group elements as its cells is also surjective.

(mathematics) A topological semigroup that is algebraically a group.

The group of self-homeomorphisms of a topological space, modulo homotopy.

plural of main group element

(astronomy) An implied cosmological scale alignment of matter. An assemblage of quasars that appear to form a structure, having them closely grouped in the sky in terms of redshift and lateral placement, implying an outline of a dimmer more massive structure in which the quasars are embedded.

(group theory) For given field F and order n, the group of n×n matrices with determinant 1, with the group operations of matrix multiplication and matrix inversion.

(group theory) For given field F and order n, the group of invertible n×n matrices, with the group operation of matrix multiplication.