Abstract
Building on the work of Mukai, we explore the birational geometry of the moduli spaces \(M_{S,L}\) of semistable rank two torsion-free sheaves, with \(c_1=-K_S\) and \(c_2=2\), on a polarized degree one del Pezzo surface (S, L); this is related to the birational geometry of the blow-up X of \(\mathbb {P}^4\) 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 \(Y=M_{S,-K_S}\), 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.
Similar content being viewed by others
Notes
A contraction is a surjective map with connected fibers \(\varphi :Y\rightarrow Z\), where Z is normal and projective.
A prime divisor E is fixed if it is a fixed component of the linear system |mE| for every \(m\ge 1\).
A facet is a face of codimension one.
A birational map \(\varphi :X_1\dasharrow X_2\) is contracting if there exist open subsets \(U_1\subseteq X_1\) and \(U_2\subseteq X_2\) such that \(\varphi \) yields an isomorphism between \(U_1\) and \(U_2\), and \({\text {codim}}(X_2\smallsetminus U_2)\ge 2\).
Note that the points \(p_i\) here depend on \(h'\), as they are the images of the exceptional divisors of \(\eta _{h'}:Y\dasharrow \mathbb {P}^4\). For simplicity we still denote them by \(p_1,\cdots ,p_8\), and similarly in the sequel of the proof.
References
Araujo, C., Casagrande, C.: On the Fano variety of linear spaces contained in two odd-dimensional quadrics. Geom. Topol. 21, 3009–3045 (2017)
Araujo, C., Massarenti, A.: Explicit log Fano structures on blow-ups of projective spaces. Proc. Lond. Math. Soc. 113, 445–473 (2016)
Batyrev, V.V., Popov, O.N.: The Cox ring of a del Pezzo surface, arithmetic of higher-dimensional algebraic varieties (Palo Alto, CA, 2002). Progr. Math. 226, 85–103 (2004)
Bauer, T., Pokora, P., Schmitz, D.: On the boundedness of the denominators in the Zariski decomposition on surfaces. J. Reine Angew. Math. 733, 251–259 (2017)
Bayer, A., Macrì, E.: MMP for moduli of sheaves on K3s via wall-crossing: nef and movable cones. Lagrangian fibrations. Invent. Math. 198, 505–590 (2014)
Beltrametti, M.C., Sommese, A.J.: The Adjunction Theory of Complex Projective Varieties, de Gruyter Expositions in Mathematics, vol. 16. Walter de Gruyter & Co., Berlin (1995)
Bertram, A., Martinez, C., Wang, J.: The birational geometry of moduli spaces of sheaves on the projective plane. Geom. Dedicata 173, 37–64 (2014)
Birkar, C., Cascini, P., Hacon, C.D., McKernan, J.: Existence of minimal models for varieties of log general type. J. Am. Math. Soc. 23, 405–468 (2010)
Blanc, J., Lamy, S.: Weak Fano threefolds obtained by blowing-up a space curve and construction of Sarkisov links. Proc. Lond. Math. Soc. 105, 1047–1075 (2012)
Casagrande, C.: Fano 4-folds, flips, and blow-ups of points. J. Algebra 483, 362–414 (2017)
Castravet, A.-M., Tevelev, J.: Hilbert’s 14th problem and Cox rings. Compos. Math. 142, 1479–1498 (2006)
Coble, A.B.: The ten nodes of the rational sextic and of the Cayley symmetroid. Am. J. Math. 41, 243–265 (1919)
Codogni, G., Fanelli, A., Svaldi, R., Tasin, L.: Fano varieties in Mori fibre spaces. Int. Math. Res. Not. 2016, 2026–2067 (2016)
Costa, L., Miró-Roig, R.M.: On the rationality of moduli spaces of vector bundles on Fano surfaces. J. Pure Appl. Algebra 137, 199–220 (1999)
Dolgachev, I.V.: Weyl groups and Cremona transformations, singularities. Proc. Symp. Part 1 (Arcata, Calif., 1981, Pure Math.) 40, 283–294 (1983)
Dolgachev, I.V.: On certain families of elliptic curves in projective space. Ann. Math. Pura Appl. 183, 317–331 (2004)
Dolgachev, I.V.: Classical Algebraic Geometry–A Modern View. Cambridge University Press, Cambridge (2012)
Dolgachev, I.V., Ortland, D.: Point sets in projective spaces and theta functions, Astérisque, vol. 165. Société Mathématique de France, Marseille (1988)
Du Val, P.: Crystallography and Cremona Transformations, The Geometric Vein—The Coxeter Festschrift, pp. 191–201. Springer, Berlin (1981)
Dumitrescu, O., Postinghel, E.: Positivity of divisors on blown-up projective spaces, I. preprint (2015). arXiv:1506.04726
Eisenbud, D., Popescu, S.: The projective geometry of the Gale transform. J. Algebra 230, 127–173 (2000)
Ellingsrud, G., Göttsche, L.: Variation of moduli space and Donaldson invariants under change of polarization. J. Reine Angew. Math. 467, 1–49 (1995)
Friedman, R.: Algebraic Surfaces and Holomorphic Vector Bundles. Universitext. Springer, Berlin (1998)
Friedman, R., Qin, Z.: Flips of moduli spaces and transition formulas for Donaldson polynomial invariants of rational surfaces. Commun. Anal. Geom. 3, 11–83 (1995)
Gómez, T.L.: Irreducibility of the moduli space of vector bundles on surfaces and Brill-Noether theory on singular curves. preprint (2000). arXiv:alg-geom/9710029v2 (Revised PhD thesis (Princeton, 1997))
Harris, J.: Algebraic Geometry-A First Course, Graduate Texts in Mathematics, vol. 133. Springer, Berlin (1992)
Hu, Y., Keel, S.: Mori dream spaces and GIT. Michigan Math. J. 48, 331–348 (2000)
Huybrechts, D., Lehn, M.: The Geometry of the Moduli Space of Sheaves, 2nd edn. Cambridge University Press, Cambridge (2010)
Kollár, J., Mori, S.: Birational Geometry of Algebraic Varieties, Cambridge Tracts in Mathematics, vol. 134. Cambridge University Press, Cambridge (1998)
Lazarsfeld, R.: Positivity in Algebraic Geometry II. Springer, Berlin (2004)
Le Potier, J.: (1992) Fibré déterminant et courbes de saut sur les surfaces algébriques, Complex projective geometry (Trieste, 1989, Bergen, 1989) London Mathematical Society Lecture Note Series, vol. 179, pp. 213–240. Cambridge University Press, Cambridge (1989)
Lesieutre, J., Park, J.: Log Fano structures and Cox rings of blow-ups of products of projective spaces. Proc. Am. Math. Soc. 145, 4201–4209 (2017)
Li, J.: Algebraic geometric interpretation of Donaldson’s polynomial invariants. J. Differ. Geom. 37, 417–466 (1993)
Matsuki, K., Wentworth, R.: Mumford-Thaddeus principle on the moduli space of vector bundles on an algebraic surface. Int. J. Math. 8, 97–148 (1997)
Moody, E.I.: Notes on the Bertini involution. Bull. Am. Math. Soc. 49, 433–436 (1943)
Mukai, S.: Counterexample to Hilbert’s fourteenth problem for the \(3\)-dimensional additive group. RIMS Preprint n. 1343, Kyoto (2001)
Mukai, S.: Geometric Realization of \(T\)-Shaped Root Systems and Counterexamples to Hilbert’s Fourteenth Problem, Algebraic Transformation Groups and Algebraic Varieties, Encyclopaedia of Mathematical Sciences, vol. 132, pp. 123–129. Springer, Berlin (2004)
Mukai, S.: Finite generation of the Nagata invariant rings in \(A\)-\(D\)-\(E\) cases. RIMS Preprint n. 1502, Kyoto (2005)
Okawa, S.: On images of Mori dream spaces. Math. Ann. 364, 1315–1342 (2016)
Yu, G. Prokhorov, Shokurov, V.V.: Towards the second main theorem on complements. J. Algebr. Geom. 18, 151–199 (2009)
Qin, Z.: Equivalence classes of polarizations and moduli spaces of sheaves. J. Differ. Geom. 37, 397–415 (1993)
Ranestad, K., Schreyer, F.-O.: Varieties of sums of powers. J. Reine Angew. Math. 2000, 147–181 (2000)
Voisin, C.: Théorie de Hodge et géométrie algébrique complexe, Cours Spécialisés, vol. 10. Société Mathématique de France, Marseille (2002)
Acknowledgements
We would like to thank Paolo Cascini, Ana-Maria Castravet, Daniele Faenzi, Emanuele Macrì, John Ottem, Zsolt Patakfalvi, and Filippo Viviani for interesting discussions related to this work, and the referees for useful comments. The first-named author has been partially supported by the PRIN 2015 “Geometria delle Varietà Algebriche”. The second-named author has been supported by the FIRB 2012 “Moduli spaces and their applications”. The third-named author has been supported by the SNF grant “Algebraic subgroups of the Cremona groups” and the DFG grant “Gromov-Witten Theorie, Geometrie und Darstellungen” (PE 2165/1-2). The second-named and third-named authors are grateful to the University of Torino for the warm hospitality provided during part of the preparation of this work.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Casagrande, C., Codogni, G. & Fanelli, A. The blow-up of \(\mathbb {P}^4\) at 8 points and its Fano model, via vector bundles on a del Pezzo surface. Rev Mat Complut 32, 475–529 (2019). https://doi.org/10.1007/s13163-018-0282-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13163-018-0282-5