Wirtinger curves, Artin groups, and hypocycloids

Autor: José Ignacio Cogolludo-Agustín, Jorge Martín-Morales, Enrique Artal Bartolo
Rok vydání: 2017
Předmět:
Zdroj: Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matemáticas. 112:641-656
ISSN: 1579-1505
1578-7303
DOI: 10.1007/s13398-017-0437-0
Popis: The computation of the fundamental group of the complement of an algebraic plane curve has been theoretically solved since Zariski-van Kampen, but actual computations are usually cumbersome. In this work, we describe the notion of Wirtinger presentation of such a group relying on the real picture of the curve and with the same combinatorial flavor as the classical Wirtinger presentation; we determine a significant family of curves for which Wirtinger presentation provides the required fundamental group. The above methods allow us to compute that fundamental group for an infinite subfamily of hypocycloids, relating them with Artin groups.
Comment: 16 pages, 8 figures, to appear in Revista de la Real Academia de Ciencias Exactas, F\'isicas y Naturales. Serie A. Matem\'aticas
Databáze: OpenAIRE