Irreducibility of− 1-classes on anticanonical rational surfaces and finite generation of the effective monoid

M Lahyane, B Harbourne - Pacific Journal of Mathematics, 2005 - msp.org
We give necessary and sufficient conditions for a divisor class on smooth projective
anticanonical rational surfaces to be the class of a smooth rational curve of self-intersection …

On the effective, nef, and semi-ample monoids of blowups of Hirzebruch surfaces at collinear points

BL de la Rosa-Navarro, JB Frías-Medina… - Canadian …, 2023 - cambridge.org
This paper is devoted to determine the geometry of a class of smooth projective rational
surfaces whose minimal models are the Hirzebruch ones; concretely, they are obtained as …

Rational surfaces having only a finite number of exceptional curves

M Lahyane - 2001 - inis.iaea.org
We characterize the rational surfaces X which have a finite number of (—l)-curves under the
assumption that—Kxis nef (ie, the intersection number ofKx with any effective divisor on X is …

On the finite generation of the monoid of effective divisor classes on rational surfaces of type (n, m)

G Failla, M Lahyane, GM Bisci - Atti della Accademia Peloritana dei …, 2006 - cab.unime.it
We prove that every projective rational surface of type (n, m) has only a finite number of (-1)
curves and only a finite number of (-2) curves, where n and m are nonnegative integers …

The finite generation of the monoid of effective divisor classes on Platonic rational surfaces

G Failla, M Lahyane, G Molica Bisci - … to Jean-Paul Brasselet on His …, 2007 - World Scientific
We prove the finite generation of the monoid of effective divisor classes on a Platonic
rational surface, then derive some consequences. We also show the vanishing of the …

Rational surfaces of Kodaira type IV

G Failla, M Lahyane, GM Bisci - Bollettino dell'Unione Matematica Italiana, 2007 - eudml.org
Abstract top We study the geometry of a rational surface of Kodaira type IV by giving the
nature of its integral curves of self-intersection less than zero, in particular we show that they …

On the finite generation of the effective monoid of rational surfaces

M Lahyane - Journal of Pure and Applied Algebra, 2010 - Elsevier
We give a numerical criterion for ensuring the finite generation of the effective monoid of the
surfaces obtained by a blowing-up of the projective plane at the supports of zero …

Exceptional curves on rational surfaces having K2⩾ 0

M Lahyane - Comptes Rendus Mathematique, 2004 - Elsevier
We characterize the rational surfaces X which have a finite number of (− 1)-curves under the
assumption that− KX is nef, where KX is a canonical divisor on X, and has self-intersection …

A geometric criterion for the finite generation of the Cox rings of projective surfaces

BLDLR Navarro, JBF Medina, M Lahyane… - Revista Matematica …, 2015 - ems.press
The aim of this paper is to give a geometric characterization of the finite generation of the
Cox rings of anticanonical rational surfaces. This characterization is encoded in the finite …

On the explicit geometry of a certain blowing-up of a smooth quadric

BL De La Rosa-Navarro, G Failla… - Analele ştiinţifice ale …, 2023 - sciendo.com
Using the high symmetry in the geometry of a smooth projective quadric, we construct
effectively new families of smooth projective rational surfaces whose nef divisors are regular …