8 papers · 1 filter
Toric non-equalized flips associated to -actions
Lorenzo Barban, Eleonora A. Romano
Starting from -actions on complex projective varieties, we construct and investigate birational maps among the corresponding extremal fixed point components. We study…
Classification of Fano 4-folds with Lefschetz defect 3 and Picard number 5
Cinzia Casagrande, Eleonora A. Romano
Let X be a smooth, complex Fano 4-fold, and rho(X) its Picard number. If X contains a prime divisor D with rho(X)-rho(D)>2, then either X is a product of del Pezzo surfaces, or rho…
High rank torus actions on contact manifolds
Gianluca Occhetta, Eleonora A. Romano, Luis E. Solá Conde +1
We prove LeBrun--Salamon conjecture in the following situation: if is a contact Fano manifold of dimension whose group of automorphisms is reductive of rank $\geq \max(2…
On some Fano 4-folds with Lefschetz defect 3
Eleonora Anna Romano
We show that Fano 4-folds with Picard number 5 have Lefschetz defect 3 if and only if they are toric of combinatorial type K. We also find a characterization for such varieties in…
A note on flatness of some fiber type contractions
Eleonora Anna Romano
We discuss the flatness property of some fiber type contractions of complex smooth projective varieties of arbitrary dimensions. We relate the flatness of some morphisms having one…
Adjunction for varieties with a action
Eleonora A. Romano, Jarosław A. Wiśniewski
Let be a complex projective manifold, an ample line bundle on , and assume that we have a action on . We classify such triples …