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K3-surfaces of genus 8 and varieties of sums of powers of cubic fourfolds

Atanas Iliev·Kristian Ranestad
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Abstract

The main outcome of this paper is that the variety VSP(F,10) of presentations of a general cubic form F in 6 variables as a sum of 10 cubes is a smooth symplectic 4-fold obtained a deformation of the Hilbert square of a K3 surface of genus 8. After publishing it in Trans. Am. Math. Soc. 353, No.4, 1455-1468 (2001), it was noted to us by Eyal Markman that in Theorem 3.17 we conclude without proof that VSP(F,10) should be the 4-fold of lines on another cubic 4-fold. We correct this in the e-print "Addendum to K3 surfaces of genus 8 and varieties of sums of powers of cubic fourfolds" (math.AG/0611533), where we establish that the general VSP(F,10) is in fact a new symplectic 4-fold different from the family of lines on a cubic 4-fold.

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Atanas Iliev, Kristian Ranestad. 2006-11-17. K3-surfaces of genus 8 and varieties of sums of powers of cubic fourfolds. https://arxiv.org/abs/math/9810121

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