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arXiv · 2104.14946

On the leading constant in the Manin-type conjecture for Campana points

Alec Shute
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Abstract

We compare the Manin-type conjecture for Campana points recently formulated by Pieropan, Smeets, Tanimoto and V\'{a}rilly-Alvarado with an alternative prediction of Browning and Van Valckenborgh in the special case of the orbifold $(\mathbb{P}^1,D)$, where $D = \frac{1}{2}[0]+\frac{1}{2}[1]+\frac{1}{2}[\infty]$. We find that the two predicted leading constants do not agree, and we discuss whether thin sets could explain this discrepancy. Motivated by this, we provide a counterexample to the Manin-type conjecture for Campana points, by considering orbifolds corresponding to squareful values of binary quadratic forms.

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Alec Shute. 2021-04-30. On the leading constant in the Manin-type conjecture for Campana points. https://arxiv.org/abs/2104.14946

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