Abstract
It follows from classical restrictions on the topology of real algebraic varieties that the first Betti number of the real part of a real nonsingular sextic in \(\mathbb {CP}^3\) can not exceed 94. We construct a real nonsingular sextic \(X\) in \(\mathbb {CP}^3\) satisfying \(b_1(\mathbb {R}X)=90\), improving a result of F. Bihan. The construction uses Viro’s patchworking and an equivariant version of a deformation due to E. Horikawa.
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Acknowledgments
I am very grateful to Erwan Brugallé and Ilia Itenberg for useful discussions and advisements. I thank also the unknown referee for useful comments on a preliminary version of this paper.
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Renaudineau, A. A real sextic surface with 45 handles. Math. Z. 281, 241–256 (2015). https://doi.org/10.1007/s00209-015-1482-z
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DOI: https://doi.org/10.1007/s00209-015-1482-z