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:
“If a dog jumps into your lap it is because he is fond of you; but if a cat does the same thing it is because your lap is warmer.”
—Alfred North Whitehead (1861–1947)
“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)