Abstract
Using a geometric approach involving Riemann surface orbifolds, we provide lower bounds for the genus of an irreducible algebraic curve of the form EA,B:A(x)-B(y)=0, where A, B∈ C(z). We also investigate “series” of curves EA , B of genus zero, where by a series we mean a family with the “same” A. We show that for a given rational function A a sequence of rational functions Bi, such that deg Bi→ ∞ and all the curves A(x) - Bi(y) = 0 are irreducible and have genus zero, exists if and only if the Galois closure of the field extension C(z) / C(A) has genus zero or one.
Original language | English |
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Pages (from-to) | 299-310 |
Number of pages | 12 |
Journal | Mathematische Zeitschrift |
Volume | 288 |
Issue number | 1-2 |
DOIs | |
State | Published - 1 Feb 2018 |
Keywords
- Galois coverings
- Rational points
- Separated variable polynomials
- Two-dimensional orbifolds
ASJC Scopus subject areas
- General Mathematics