De Rham invariant

In geometric topology, the de Rham invariant is a mod 2 invariant of a (4k+1)-dimensional manifold, that is, an element of – either 0 or 1. It can be thought of as the simply-connected symmetric L-group and thus analogous to the other invariants from L-theory: the signature, a 4k-dimensional invariant (either symmetric or quadratic, ), and the Kervaire invariant, a (4k+2)-dimensional quadratic invariant

It is named for Swiss mathematician Georges de Rham, and used in surgery theory.[1][2]

  1. ^ Morgan, John W; Sullivan, Dennis P. (1974), "The transversality characteristic class and linking cycles in surgery theory", Annals of Mathematics, 2, 99 (3): 463–544, doi:10.2307/1971060, JSTOR 1971060, MR 0350748
  2. ^ John W. Morgan, A product formula for surgery obstructions, 1978