A note on SG points for reduced plane curves

Aki Ikeda; Takeshi Takahashi

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arXiv · 2606.01924

A note on SG points for reduced plane curves

Aki Ikeda·Takeshi Takahashi

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Abstract

In our previous work, we generalized the concept of Galois points for irreducible plane curves to the case of reduced plane curves. We also introduced the concept of simultaneous Galois points, which is an equivalent concept to Galois points, and studied their number when the irreducible components are nonsingular. In this paper, we consider the remaining cases where the irreducible components are of degree $d=2$ or $3$. For the case of $d=2$, we establish a generalized version of the theorem in our previous paper. For the case of $d=3$, we classify simultaneous Galois points into the first and second kinds. We give a necessary condition for the former and provide examples for the latter.

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Aki Ikeda, Takeshi Takahashi. 2026-06-01. A note on SG points for reduced plane curves. https://arxiv.org/abs/2606.01924

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