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)
“Even in harmonious families there is this double life: the group life, which is the one we can observe in our neighbour’s household, and, underneath, another—secret and passionate and intense—which is the real life that stamps the faces and gives character to the voices of our friends. Always in his mind each member of these social units is escaping, running away, trying to break the net which circumstances and his own affections have woven about him.”
—Willa Cather (1873–1947)