manifolds and cobordisms
cobordism theory, Introduction
Definitions
Genera and invariants
Classification
Theorems
For a framed smooth manifold of dimension , , the Kervaire invariant or Arf-Kervaire invariant
with values in the group of order 2 is the Arf invariant of the skew-quadratic form on the middle dimensional homology group (the intersection pairing).
Manifolds with non-trivial Kervaire invariant, hence with Kervaire invariant 1, exist in dimension
This is the statement of (the solution to) the Arf-Kervaire invariant problem.
On a surface a framing is equivalently a spin structure. If the surface carries a complex manifold structure then a spin structure is equivalently a theta characteristic, hence a square root of the canonical bundle. Given this, the Kervaire invariant in is equal to the dimension mod 2
of the space of holomorphic sections of :
manifold dimension | invariant | quadratic form | quadratic refinement |
---|---|---|---|
signature genus | intersection pairing | integral Wu structure | |
Kervaire invariant | framing |
W. Browder, The Kervaire invariant of framed manifolds and its generalization, Annals of Mathematics 90 (1969), 157–186.
John Jones, Elmer Rees, A note on the Kervaire invariant (pdf)
Wikipedia, Kervaire invariant
On the solution of the Arf-Kervaire invariant problem away from :
On the equivariant homotopy theory involved:
More resources are collected at:
Solution to the last remaining case, , is claimed in:
Last revised on May 17, 2025 at 09:20:09. See the history of this page for a list of all contributions to it.