On the gonality sequence of smooth curves: normalizations of singular curves in a quadric surface
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Abstract
Let C be a smooth curve of genus g. For each positive integer r, the r-gonality d r (C) of C is the minimal integer t such that there is \(L\in \operatorname{Pic}^{t}(C)\) with h 0(C,L)=r+1. In this paper, for all g≥40805 we construct several examples of smooth curves C of genus g with d 3(C)/3<d 4(C)/4, i.e. for which a slope inequality fails.
Keywords
Gonality sequence Smooth curveMathematics Subject Classification (2000)
14H45 14H50Notes
Acknowledgements
I want to thank the referee for several extremely useful remarks (in this version Step (⋄) of the proof of Proposition 1 is due to the referee).
The author was partially supported by MIUR and GNSAGA of INdAM (Italy)
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© Institute of Mathematics, Vietnam Academy of Science and Technology (VAST) and Springer Science+Business Media Singapore 2013