Abstract
In this text we show that the deformation space of a nodal surface X of degree d is smooth and of the expected dimension if \(d\le 7\) or \(d\ge 8\) and X has at most \(4d-5\) nodes (The case \(d\le 7\) was previously covered by Alexandru Dimca using different techniques). For \(d\ge 8\) we give explicit examples of nodal surfaces with \(4d-4\) nodes, for which the tangent space to the deformation space has larger dimension than expected.
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The author would like to thank Arnaud Beauville for pointing out the paper [3]. The author would thank the referee for many valuable suggestions to improve the exposition.
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Kloosterman, R. Nodal surfaces with obstructed deformations. Geom Dedicata 190, 143–150 (2017). https://doi.org/10.1007/s10711-017-0232-2
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DOI: https://doi.org/10.1007/s10711-017-0232-2