Wiktionary
n. (context mathematics English) The mathematical theory of groups.
WordNet
n. the branch of mathematics dealing with groups
Wikipedia
In mathematics and abstract algebra, group theory studies the algebraic structures known as groups. The concept of a group is central to abstract algebra: other well-known algebraic structures, such as rings, fields, and vector spaces, can all be seen as groups endowed with additional operations and axioms. Groups recur throughout mathematics, and the methods of group theory have influenced many parts of algebra. Linear algebraic groups and Lie groups are two branches of group theory that have experienced advances and have become subject areas in their own right.
Various physical systems, such as crystals and the hydrogen atom, may be modelled by symmetry groups. Thus group theory and the closely related representation theory have many important applications in physics, chemistry, and materials science. Group theory is also central to public key cryptography.
One of the most important mathematical achievements of the 20th century was the collaborative effort, taking up more than 10,000 journal pages and mostly published between 1960 and 1980, that culminated in a complete classification of finite simple groups.
Usage examples of "group theory".
Sarato emerged from Lejeune's discussion of group theory (the natives had already developed that, so the talk was a mere comparison of approaches) to show me his obsidian-edged tools.
As Orlando had put it-groping for a three-dimensional analogy when Yatima had started spouting group theory and topology-it was like sliding down into the particle's wormhole on the banister of a spiral staircase.
The giant calculators may solve or partially solve the equations of group theory needed in analyzing a rotor machine.