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:
“Knowledge shrinks as wisdom grows.”
—Alfred North Whitehead (1861–1947)
“He hung out of the window a long while looking up and down the street. The world’s second metropolis. In the brick houses and the dingy lamplight and the voices of a group of boys kidding and quarreling on the steps of a house opposite, in the regular firm tread of a policeman, he felt a marching like soldiers, like a sidewheeler going up the Hudson under the Palisades, like an election parade, through long streets towards something tall white full of colonnades and stately. Metropolis.”
—John Dos Passos (1896–1970)