Results 11 to 20 of about 471 (42)
Effective characterization of quasi-abelian surfaces
Forum of Mathematics, Sigma, 2023 Let V be a smooth quasi-projective complex surface such that the first three logarithmic plurigenera $\overline P_1(V)$ , $\overline P_2(V)$ and $\overline P_3(V)$ are equal to 1 and the logarithmic irregularity $\overline q(V)$
Margarida Mendes Lopes +2 more
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FANO HYPERSURFACES WITH ARBITRARILY LARGE DEGREES OF IRRATIONALITY
Forum of Mathematics, Sigma, 2020 We show that complex Fano hypersurfaces can have arbitrarily large degrees of irrationality. More precisely, if we fix a Fano index $e$, then the degree of irrationality of a very general complex Fano hypersurface of index $e$ and dimension n is bounded ...
NATHAN CHEN, DAVID STAPLETON
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Conic bundles that are not birational to numerical Calabi--Yau pairs [PDF]
Épijournal de Géométrie Algébrique, 2017 Let $X$ be a general conic bundle over the projective plane with branch curve of degree at least 19. We prove that there is no normal projective variety $Y$ that is birational to $X$ and such that some multiple of its anticanonical divisor is effective ...
János Kollár
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Singular del Pezzo fibrations and birational rigidity [PDF]
, 2014 A known conjecture of Grinenko in birational geometry asserts that a Mori fibre space with the structure of del Pezzo fibration of low degree is birationally rigid if and only if its anticanonical class is an interior point in the cone of mobile divisors.
A. Corti +8 more
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Algebraic models of the Euclidean plane [PDF]
Épijournal de Géométrie Algébrique, 2018 We introduce a new invariant, the real (logarithmic)-Kodaira dimension, that allows to distinguish smooth real algebraic surfaces up to birational diffeomorphism.
Jérémy Blanc, Adrien Dubouloz
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Homogeneous Polynomials with Isomorphic Milnor Algebras [PDF]
, 2008 In Theorem 3.2 we show that two homogeneous polynomials $f$ and $g$ having isomorphic Milnor algebras are right-equivalent.Comment: 6 ...
A. Dimca +4 more
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Cubic symmetroids and vector bundles on a quadric surface [PDF]
, 2012 We investigate the jumping conics of stable vector bundles $\Ee$ of rank 2 on a smooth quadric surface $Q$ with the Chern classes $c_1=\Oo_Q(-1,-1)$ and $c_2=4$ with respect to the ample line bundle $\Oo_Q(1,1)$. We describe the set of jumping conics of $
Huh, Sukmoon
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The boundary of the orbit of the 3 by 3 determinant polynomial [PDF]
, 2016 We consider the 3 by 3 determinant polynomial and we describe the limit points of the set of all polynomials obtained from the determinant polynomial by linear change of variables. This answers a question of J.
Hüttenhain, Jesko, Lairez, Pierre
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Equivalent birational embeddings [PDF]
, 2009 Let $X$ be a projective variety of dimension $r$ over an algebraically closed field. It is proven that two birational embeddings of $X$ in $\P^n$, with $n\geq r+2$ are equivalent up to Cremona transformations of $\P^n$
Mella, Massimiliano, Polastri, Elena
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Multiplicity of the saturated special fiber ring of height two perfect ideals [PDF]
, 2019 Let $R$ be a polynomial ring and $I \subset R$ be a perfect ideal of height two minimally generated by forms of the same degree. We provide a formula for the multiplicity of the saturated special fiber ring of $I$. Interestingly, this formula is equal to
Cid-Ruiz, Yairon
core +4 more sources