English

Fake Real Planes: exotic affine algebraic models of $\mathbb{R}^2$

Algebraic Geometry 2022-06-13 v2

Abstract

We study real rational models of the euclidean plane R2\mathbb{R}^2 up to isomorphisms and up to birational diffeomorphisms. The analogous study in the compact case, that is the classification of real rational models of the real projective plane RP2\mathbb{R}\mathbb{P}^2 is well known: up to birational diffeomorphisms, there is only one model. A fake real plane is a nonsingular affine surface defined over the reals with homologically trivial complex locus and real locus diffeomorphic to R2\mathbb{R}^2 but which is not isomorphic to the real affine plane. We prove that fake planes exist by giving many examples and we tackle the question: does there exist fake planes whose real locus is not birationally diffeomorphic to the real affine plane?

Keywords

Cite

@article{arxiv.1507.01574,
  title  = {Fake Real Planes: exotic affine algebraic models of $\mathbb{R}^2$},
  author = {Adrien Dubouloz and Frédéric Mangolte},
  journal= {arXiv preprint arXiv:1507.01574},
  year   = {2022}
}