On Barth's restriction theorem.
On base change theorem and coherence in rigid cohomology.
On Brauer groups of real Enriques surfaces.
On Buchsbaum bundles on quadric hypersurfaces
Let E be an indecomposable rank two vector bundle on the projective space ℙn, n ≥ 3, over an algebraically closed field of characteristic zero. It is well known that E is arithmetically Buchsbaum if and only if n = 3 and E is a null-correlation bundle. In the present paper we establish an analogous result for rank two indecomposable arithmetically Buchsbaum vector bundles on the smooth quadric hypersurface Q n ⊂ ℙn+1, n ≥ 3. We give in fact a full classification and prove that n must be at most...
On classification of semigroup rings.
On Clifford's theorem for rank-3 bundles.
In this paper we obtain bounds on h0(E) where E is a semistable bundle of rank 3 over a smooth irreducible projective curve X of genus g ≥ 2 defined over an algebraically closed field of characteristic 0. These bounds are expressed in terms of the degrees of stability s1(E), s2(E). We show also that in some cases the bounds are best possible. These results extend recent work of J. Cilleruelo and I. Sols for bundles of rank 2.
On cohomological systems of Galois representations
The paper contains an expanded version of the talk delivered by the first author during the conference ALANT3 in Będlewo in June 2014. We survey recent results on independence of systems of Galois representations attached to ℓ-adic cohomology of schemes. Some other topics ranging from the Mumford-Tate conjecture and the Geyer-Jarden conjecture to applications of geometric class field theory are also considered. In addition, we have highlighted a variety of open questions which can lead to interesting...
On complex vector bundles on projective threefolds.
On compositions and triality.
On connected divisors.
On deformation of maximally degenerate stable marked curves and Oda's problem.
On desingularized Horrocks-Mumford quintics.
On direct and inverse images of D-Modules in prime characteristic.
On Donaldson polynomials of rational ruled surfaces.
On Extremal Rational Elliptic Surfaces.
On families of pure slope -functions.
On fundamental groups of algebraic varieties and value distribution theory
If a smooth projective variety admits a non-degenerate holomorphic map from the complex plane , then for any finite dimensional linear representation of the fundamental group of the image of this representation is almost abelian. This supports a conjecture proposed by F. Campana, published in this journal in 2004.
On Galois module structure of the cohomology groups of an algebraic variety.
On generalized Cauchy-Riemann equations on manifolds
On generation of jets for vector bundles.
We introduce and study the k-jet ampleness and the k-jet spannedness for a vector bundle, E, on a projective manifold. We obtain different characterizations of projective space in terms of such positivity properties for E. We compare the 1-jet ampleness with different notions of very ampleness in the literature.