$\boldsymbol{Q}$-factorial Gorenstein toric Fano varieties with large Picard number
Nill, Benjamin ; Øbro, Mikkel
Tohoku Math. J. (2), Tome 62 (2010) no. 1, p. 1-15 / Harvested from Project Euclid
In dimension $d$, ${\boldsymbol Q}$-factorial Gorenstein toric Fano varieties with Picard number $\rho_X$ correspond to simplicial reflexive polytopes with $\rho_X + d$ vertices. Casagrande showed that any $d$-dimensional simplicial reflexive polytope has at most $3 d$ and $3d-1$ vertices if $d$ is even and odd, respectively. Moreover, for $d$ even there is up to unimodular equivalence only one such polytope with $3 d$ vertices, corresponding to the product of $d/2$ copies of a del Pezzo surface of degree six. In this paper we completely classify all $d$-dimensional simplicial reflexive polytopes having $3d-1$ vertices, corresponding to $d$-dimensional ${\boldsymbol Q}$-factorial Gorenstein toric Fano varieties with Picard number $2d-1$. For $d$ even, there exist three such varieties, with two being singular, while for $d > 1$ odd there exist precisely two, both being nonsingular toric fiber bundles over the projective line. This generalizes recent work of the second author.
Publié le : 2010-05-15
Classification:  toric varieties,  Fano varieties,  lattice polytopes,  14M25,  14J45,  52B20
@article{1270041023,
     author = {Nill, Benjamin and \O bro, Mikkel},
     title = {$\boldsymbol{Q}$-factorial Gorenstein toric Fano varieties with large Picard number},
     journal = {Tohoku Math. J. (2)},
     volume = {62},
     number = {1},
     year = {2010},
     pages = { 1-15},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1270041023}
}
Nill, Benjamin; Øbro, Mikkel. $\boldsymbol{Q}$-factorial Gorenstein toric Fano varieties with large Picard number. Tohoku Math. J. (2), Tome 62 (2010) no. 1, pp.  1-15. http://gdmltest.u-ga.fr/item/1270041023/