Positive-definite quadratic bundles over the plane.
Positivity and Kleiman transversality in equivariant -theory of homogeneous spaces
We prove the conjectures of Graham–Kumar [GrKu08] and Griffeth–Ram [GrRa04] concerning the alternation of signs in the structure constants for torus-equivariant -theory of generalized flag varieties . These results are immediate consequences of an equivariant homological Kleiman transversality principle for the Borel mixing spaces of homogeneous spaces, and their subvarieties, under a natural group action with finitely many orbits. The computation of the coefficients in the expansion of the equivariant...
Positivity of Schur function expansions of Thom polynomials
Combining the approach to Thom polynomials via classifying spaces of singularities with the Fulton-Lazarsfeld theory of cone classes and positive polynomials for ample vector bundles, we show that the coefficients of the Schur function expansions of the Thom polynomials of stable singularities are nonnegative with positive sum.
Positivity of Thom polynomials II: the Lagrange singularities
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
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.
Positivity properties of toric vector bundles
We show that a torus-equivariant vector bundle on a complete toric variety is nef or ample if and only if its restriction to every invariant curve is nef or ample, respectively. Furthermore, we show that nef toric vector bundles have a nonvanishing global section at every point and deduce that the underlying vector bundle is trivial if and only if its restriction to every invariant curve is trivial. We apply our methods and results to study, in particular, the vector bundles that arise as the...
Positivity results for Euler characteristics of singular surfaces.
Postulation and gonality for projective curves
Postulation of Canonical Curves in IP3.
Potential theory and Lefschetz theorems for arithmetic surfaces
Potenzreihenerweiterung und formale Fasern in lokalen Ringen mit Approximationseigenschaft.
Pour une théorie inconditionnelle des motifs
Power reductivity over an arbitrary base.
Power Series Solutions of Algebraic Differential Equations.
Power-free values, large deviations, and integer points on irrational curves
Let be a polynomial of degree without roots of multiplicity or . Erdős conjectured that, if satisfies the necessary local conditions, then is free of th powers for infinitely many primes . This is proved here for all with sufficiently high entropy.The proof serves to demonstrate two innovations: a strong repulsion principle for integer points on curves of positive genus, and a number-theoretical analogue of Sanov’s theorem from the theory of large deviations.
Poznámka k theorii trochoid
Poznámka o Clebschově diagonální ploše
Poznámka o parabolické křivce plochy třetího stupně
Poznámka o prostorové kollineaci
Poznámky o ploše třetího stupně s oskulačním kuželem