Genus zero of projective symplectic groups

A transitive subgroup G ≤ SN is called a genus zero group if there exist non identity elements x1 , . . . , xr∈G satisfying G =<x1, . . . , xr>, x1·...·xr=1 and ind x1+...+ind xr = 2N − 2. The Hurwitz space Hinr(G) is the space of genus zero coverings of the Riemann sphere P1 with r branch po...

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Main Authors: H.M Mohammed Salih, Rezhna M. Rezhna M. Hussein
Format: Article
Language:English
Published: University of Extremadura 2022-07-01
Series:Extracta Mathematicae
Subjects:
Online Access:https://publicaciones.unex.es/index.php/EM/article/view/1359
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author H.M Mohammed Salih
Rezhna M. Rezhna M. Hussein
author_facet H.M Mohammed Salih
Rezhna M. Rezhna M. Hussein
author_sort H.M Mohammed Salih
collection DOAJ
description A transitive subgroup G ≤ SN is called a genus zero group if there exist non identity elements x1 , . . . , xr∈G satisfying G =<x1, . . . , xr>, x1·...·xr=1 and ind x1+...+ind xr = 2N − 2. The Hurwitz space Hinr(G) is the space of genus zero coverings of the Riemann sphere P1 with r branch points and the monodromy group G. In this paper, we assume that G is a finite group with PSp(4, q) ≤ G ≤ Aut(PSp(4, q)) and G acts on the projective points of 3-dimensional projective geometry PG(3, q), q is a prime power. We show that G possesses no genus zero group if q > 5. Furthermore, we study the connectedness of the Hurwitz space Hinr(G) for a given group G and q ≤ 5.
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spelling doaj.art-d95fb38d8dd946fea32a032cf77a11462022-12-22T01:40:57ZengUniversity of ExtremaduraExtracta Mathematicae0213-87432605-56862022-07-01Genus zero of projective symplectic groupsH.M Mohammed Salih0Rezhna M. Rezhna M. Hussein1Department of Mathematics, Faculty of Science, Soran University Kawa St. Soran, Erbil, IraqDepartment of Mathematics, Faculty of Science, Soran University Kawa St. Soran, Erbil, Iraq A transitive subgroup G ≤ SN is called a genus zero group if there exist non identity elements x1 , . . . , xr∈G satisfying G =<x1, . . . , xr>, x1·...·xr=1 and ind x1+...+ind xr = 2N − 2. The Hurwitz space Hinr(G) is the space of genus zero coverings of the Riemann sphere P1 with r branch points and the monodromy group G. In this paper, we assume that G is a finite group with PSp(4, q) ≤ G ≤ Aut(PSp(4, q)) and G acts on the projective points of 3-dimensional projective geometry PG(3, q), q is a prime power. We show that G possesses no genus zero group if q > 5. Furthermore, we study the connectedness of the Hurwitz space Hinr(G) for a given group G and q ≤ 5. https://publicaciones.unex.es/index.php/EM/article/view/1359symplectic groupfixed pointgenus zero group
spellingShingle H.M Mohammed Salih
Rezhna M. Rezhna M. Hussein
Genus zero of projective symplectic groups
Extracta Mathematicae
symplectic group
fixed point
genus zero group
title Genus zero of projective symplectic groups
title_full Genus zero of projective symplectic groups
title_fullStr Genus zero of projective symplectic groups
title_full_unstemmed Genus zero of projective symplectic groups
title_short Genus zero of projective symplectic groups
title_sort genus zero of projective symplectic groups
topic symplectic group
fixed point
genus zero group
url https://publicaciones.unex.es/index.php/EM/article/view/1359
work_keys_str_mv AT hmmohammedsalih genuszeroofprojectivesymplecticgroups
AT rezhnamrezhnamhussein genuszeroofprojectivesymplecticgroups