All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 3 Next

Displaying 41 – 60 of 70

Showing per page

Positivity of Thom polynomials II: the Lagrange singularities

Małgorzata Mikosz, Piotr Pragacz, Andrzej Weber (2009)

Fundamenta Mathematicae

We study Thom polynomials associated with Lagrange singularities. We expand them in the basis of Q̃-functions. This basis plays a key role in the Schubert calculus of isotropic Grassmannians. We prove that the Q̃-function expansions of the Thom polynomials of Lagrange singularities always have nonnegative coefficients. This is an analog of a result on the Thom polynomials of mapping singularities and Schur S-functions, established formerly by the last two authors.

Positivity on subvarieties and vanishing of higher cohomology

Alex Küronya (2013)

Annales de l’institut Fourier

We study the relationship between positivity of restriction of line bundles to general complete intersections and vanishing of their higher cohomology. As a result, we extend classical vanishing theorems of Kawamata–Viehweg and Fujita to possibly non-nef divisors.

Predegree Polynomials of Plane Configurations in Projective Space

Tzigantchev, Dimitre (2008)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 14N10, 14C17.We work over an algebraically closed field of characteristic zero. The group PGL(4) acts naturally on PN which parameterizes surfaces of a given degree in P3. The orbit of a surface under this action is the image of a rational map PGL(4) ⊂ P15→PN. The closure of the orbit is a natural and interesting object to study. Its predegree is defined as the degree of the orbit closure multiplied by the degree of the above map restricted to a general Pj,...

Projective normality of abelian varieties with a line bundle of type 2 , ⋯

Elena Rubei (1998)

Bollettino dell'Unione Matematica Italiana

Sia X una varietà abeliana e L un fibrato in rette ampio di tipo 2 , 2 ⁢ d 2 , … , 2 ⁢ d g su X ; sia φ L l'applicazione associata a L . In questo lavoro si dimostra il seguente fatto: se d i ≤ 2 per qualsiasi i , L non è mai normalmente generato (quindi, se φ L è un embedding, φ L ⁢ X non è proiettivamente normale); negli altri casi invece L è normalmente generato per X , c 1 ⁢ L generico nello spazio dei moduli delle varietà abeliane polarizzate di tipo 2 , 2 ⁢ d 2 , … , 2 ⁢ d g .

Currently displaying 41 – 60 of 70