4 papers
On ordinarity and lifting fibrations on surfaces
Celalettin Kaya, Hursit Onsiper
We investigate the relation between the ordinarity of a surface and of its Picard scheme in connection with the problem of lifting fibrations of genus g > 1 on surfaces to characte…
On Deformations and Moduli of Genus 2 Fibrations
Hursit Onsiper
In this paper, we investigate the moduli of surfaces of general type admitting genus 2 fibrations with irregularity q = g_b + 1, where g_b >= 2 is the genus of the base. We prove t…
Generalized Shioda-Inose Structures on K3 Surfaces
H. Onsiper, S. Sertoz
We examine the finite group actions on K3 and Abelian surfaces giving the same orbit space after desingularization. We show that when the group is not Z_2, then the Picard number o…
On Degenerations of Fibre Spaces of Curves of Genus >= 2
Hursit Onsiper, Sinan Sertoz
In this note, we show that for surfaces admitting suitable fibrations, any given degeneration X / Delta is bimeromorphic to a fiber space over Delta and we apply this result to the…