In mathematics, in the sub-field of geometric topology, the mapping class group is an important algebraic invariant of a topological space. Briefly, the mapping class group is a discrete group of 'symmetries' of the space.
Read more about Mapping Class Group: Motivation, Definition, Mapping-class Groups of Pairs, Torelli Group, Stable Mapping Class Group
Famous quotes containing the words class and/or group:
“History is full, down to this day, of the imbecility of kings and governors. They are a class of persons much to be pitied, for they know not what they should do.”
—Ralph Waldo Emerson (1803–1882)
“It’s important to remember that feminism is no longer a group of organizations or leaders. It’s the expectations that parents have for their daughters, and their sons, too. It’s the way we talk about and treat one another. It’s who makes the money and who makes the compromises and who makes the dinner. It’s a state of mind. It’s the way we live now.”
—Anna Quindlen (20th century)