Whitehead Group

Whitehead group in mathematics may mean:

  • A group W with Ext(W, Z)=0; see Whitehead problem
  • For a ring, the Whitehead group Wh(A) of a ring A, equal to
  • For a group, the Whitehead group Wh(G) of a group G, equal to K1(Z)/{±G}. Note that this is a quotient of the Whitehead group of the group ring.
  • The Whitehead group Wh(A) of a simplicial complex or PL-manifold A, equal to Wh(π1(A)); see Whitehead torsion.

All named after J. H. C. Whitehead.

Famous quotes containing the words whitehead and/or group:

    Every philosophy is tinged with the colouring of some secret imaginative background, which never emerges explicitly into its train of reasoning.
    —Alfred North Whitehead (1861–1947)

    The virtue of dress rehearsals is that they are a free show for a select group of artists and friends of the author, and where for one unique evening the audience is almost expurgated of idiots.
    Alfred Jarry (1873–1907)