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تسجيل مستخدم جديدAlmost-Regular Dessins on a Sphere and Torus
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The Hurwitz problem asks which ramification data are realizable, that is appear as the ramification type of a covering. We use dessins denfant to show that families of genus 1 regular ramification data with small changes are realizable with the exception of four families which were recently shown to be nonrealizable. A similar description holds in the case of genus 0 ramification data.
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