Mapping Class Group - Mapping-class Groups of Pairs

Mapping-class Groups of Pairs

Given a pair of spaces (X,A) the mapping class group of the pair is the isotopy-classes of automorphisms of the pair, where an automorphism of (X,A) is defined as an automorphism of X that preserves A, i.e. f: XX is invertible and f(A) = A.

Read more about this topic:  Mapping Class Group

Famous quotes containing the word groups:

    Trees appeared in groups and singly, revolving coolly and blandly, displaying the latest fashions. The blue dampness of a ravine. A memory of love, disguised as a meadow. Wispy clouds—the greyhounds of heaven.
    Vladimir Nabokov (1899–1977)