RT Journal Article T1 Alternating groups as automorphism groups of Riemann surfaces A1 Etayo Gordejuela, J. Javier A1 Martínez García, Ernesto AB In this work we give pairs of generators (x, y) for the alternating groups An, 5 ≤ n ≤ 19, such that they determine the minimal genus of a Riemann surface on which An acts as the automorphism group. Using these results we prove that A15 is the unique of these groups that is an H*-group, i.e., the groups achieving the upper bound of the order of an automorphism group acting on non-orientable unbordered surfaces. PB World Scientific SN 0218-1967 YR 2006 FD 2006 LK https://hdl.handle.net/20.500.14352/50031 UL https://hdl.handle.net/20.500.14352/50031 NO N. L. Alling and N. Greenleaf, Foundations of the Theory of Klein Surfaces, Lecture Notes in Mathematics, Vol. 219 (Springer, Berlin-Heidelberg-New York, 1971). M. D. E. Conder, Some results on quotients of triangle groups, Bull. Austral. Math. Soc. 29 (1984) 73–90. J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, The ATLAS of Finite Groups (Oxford University Press, 1985). J. J. Etayo and E. Martínez, Alternating groups, Hurwitz groups and H ∗ -groups, J. Algebra 283 (2005) 327–349. A. M. Macbeath, The classification of non-Euclidean crystallographic groups, Canad. J. Math. 6 (1967) 1192–1205. C. L. May, Large automorphism groups of compact Klein surfaces with boundary, Glasgow Math. J. 18 (1977) 1–10. R. Preston, Projective structures and fundamental domains on compact Klein surfaces, Thesis, University of Texas (1975). D. Singerman, Automorphisms of compact non-orientable Riemann surfaces, Glasgow Math. J. 12 (1971) 50–59. D. Singerman, On the structure of non-Euclidean crystallographic groups, Proc. Cambridge Phil. Soc. 76 (1974) 233–240. H. C. Wilkie, On non-Euclidean crystallographic groups, Math. Z. 91 (1966) 87–102. DS Docta Complutense RD 6 may 2024