Results 81 to 90 of about 10,755 (178)
Noether-Fano Inequalities and Canonical Thresholds on Fano Varieties
, 2021 We prove a more general and precise version of the Noether-Fano inequalities for birational maps between Mori fiber spaces. This is applied to give descriptions of global canonical thresholds on Fano varieties of Picard number one.
openaire +2 more sources
Some adjunction properties of ample vector bundles II
Le Matematiche, 2001 Let E be a vector bundle of rank r on a projective variety X of dimension n with only log-terminal singularities. We classify the couples (E,X) satisfying some conditions. We give some applications in case of sectional genus one.
Hironobu Ishihara
doaj
Flexible affine cones and flexible coverings
, 2016 We provide a new criterion for flexibility of cones over varieties covered by flexible affine varieties. We apply this criterion to prove flexibility of affine cones over secant varieties of Segre--Veronese embeddings and over certain Fano threefolds. We
Michałek, Matheusz +2 more
core
Covered by lines and Conic connected varieties
Le Matematiche, 2011 We study some properties of an embedded variety covered by lines and give a numerical criterion ensuring the existence of a singular conic through two of its general points. We show that our criterion is sharp.
Alex Massarenti +2 more
doaj
On some invariants of cubic fourfolds. [PDF]
Eur J Math, 2023 Gounelas F, Kouvidakis A.
europepmc +1 more source
Toric Fano varieties and birational morphisms
, 2001 In this paper we study smooth toric Fano varieties using primitive relations and toric Mori theory. We show that for any irreducible invariant divisor D in a toric Fano variety X, we have $0\leq _X- _D\leq 3$, for the difference of the Picard numbers of X and D. Moreover, if $ _X- _D>0$ (with some additional hypotheses if $ _X- _D=1$), we give
openaire +4 more sources
On Fano and weak Fano Bott–Samelson–Demazure–Hansen varieties
Journal of Pure and Applied Algebra, 2018 Accepted in Journal of Pure and Applied ...
openaire +4 more sources
Categorical Torelli theorems: results and open problems. [PDF]
Rend Circ Mat Palermo, 2023 Pertusi L, Stellari P.
europepmc +1 more source
Boundedness of spherical Fano varieties
, 2003 We prove that for any e>0, there exists only finitely many e-log terminal spherical Fano varieties of fixed dimension. We also introduce an invariant of a spherical subgroup H in a reductive group G which measures how nice an equivariant Fano compactification G/H there exists.
Alexeev, Valery, Brion, Michel
openaire +2 more sources
Maximally mutable Laurent polynomials. [PDF]
Proc Math Phys Eng Sci, 2021 Coates T +3 more
europepmc +1 more source