16 citations · 23 across the 10 of their papers we have counts for
10 papers
Immersed projective planes, Arf invariants and even 4-manifolds
Christian Bohr
In this paper, we exploit a subtle indeterminacy in the definition of the spherical Kervaire-Milnor invariant which was discovered by R. Stong to construct non-spin 4-manifolds wit…
Embedded spheres and 4-manifolds with spin coverings
Christian Bohr
A strategy for constructing an embedded sphere in a 4-manifold realizing a given homology class which has been successfully applied in the past is to represent the class as a first…
On the kinkiness of closed braids
Christian Bohr
In this note, we prove a lower bound for the positive kinkiness of a closed braid which we then use to derive an estimate for the positive kinkiness of a link in terms of its Seife…
Homology cobordism and classical knot invariants
Christian Bohr, Ronnie Lee
In this paper we define and investigate Z/2-homology cobordism invariants of Z/2-homology 3-spheres which turn out to be related to classical invariants of knots. As an application…
Stabilisation, bordism and embedded spheres in 4--manifolds
Christian Bohr
It is one of the most important facts in 4-dimensional topology that not every spherical homology class of a 4-manifold can be represented by an embedded sphere. In 1978, M. Freedm…
Cycles, submanifolds, and structures on normal bundles
C. Bohr, B. Hanke, D. Kotschick
We give explicit examples of degree 3 cohomology classes not Poincare dual to submanifolds, and discuss the realisability of homology classes by submanifolds with Spin-C normal bun…