English

Degree Theory of Immersed Hypersurfaces

Differential Geometry 2016-10-11 v3

Abstract

We develop a degree theory for compact immersed hypersurfaces of prescribed KK-curvature immersed in a compact, orientable Riemannian manifold, where KK is any elliptic curvature function. We apply this theory to count the (algebraic) number of immersed hyperspheres in various cases: where KK is mean curvature; extrinsic curvature and special Lagrangian curvature, and we show that in all these cases, this number is equal to χ(M)-\chi(M), where χ(M)\chi(M) is the Euler characteristic of MM.

Keywords

Cite

@article{arxiv.1010.1879,
  title  = {Degree Theory of Immersed Hypersurfaces},
  author = {Harold Rosenberg and Graham Smith},
  journal= {arXiv preprint arXiv:1010.1879},
  year   = {2016}
}

Comments

Complete revision. We've worked hard to make the text clearer and we hope the reader will notice the difference. Shorter and more conceptual proofs. The applications, we hope, are much clearer. In addition, we develop a new concept of "weakly smooth manifolds". This provides a nice smooth manifold structure for the space of unparametrised immersions (details in the introduction)