Building on the work of Mukai, we explore the birational geometry of the moduli spaces MS,L of semistable rank two torsion-free sheaves, with c1=-KS and c2=2, on a polarized degree one del Pezzo surface (S,L); this is related to the birational geometry of the blow-up X of P4 in 8 points. Our analysis is explicit and is obtained by looking at the variation of stability conditions. Then we provide a careful investigation of the blow-up X and of the moduli space Y=MS,-KS, which is a remarkable family of smooth Fano fourfolds. In particular we describe the relevant cones of divisors of Y, the group of automorphisms, and the base loci of the anticanonical and bianticanonical linear systems.
Casagrande, C., Codogni, G., Fanelli, A. (2019). The blow-up of P 4 at 8 points and its Fano model, via vector bundles on a del Pezzo surface. REVISTA MATEMATICA COMPLUTENSE, 32(2), 475-529 [10.1007/s13163-018-0282-5].
The blow-up of P 4 at 8 points and its Fano model, via vector bundles on a del Pezzo surface
Codogni G.;
2019-01-01
Abstract
Building on the work of Mukai, we explore the birational geometry of the moduli spaces MS,L of semistable rank two torsion-free sheaves, with c1=-KS and c2=2, on a polarized degree one del Pezzo surface (S,L); this is related to the birational geometry of the blow-up X of P4 in 8 points. Our analysis is explicit and is obtained by looking at the variation of stability conditions. Then we provide a careful investigation of the blow-up X and of the moduli space Y=MS,-KS, which is a remarkable family of smooth Fano fourfolds. In particular we describe the relevant cones of divisors of Y, the group of automorphisms, and the base loci of the anticanonical and bianticanonical linear systems.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
