11 papers · 1 filter
Monodromy of stratified vector bundles
Indranil Biswas, Manish Kumar, A. J. Parameswaran
We explore the interconnections between the monodromy group of stratified bundles on a smooth projective variety and the monodromy of the strongly semistable vector bundles …
On the Harder-Narasimhan filtration of the direct image of the structure sheaf
Indranil Biswas, Manish Kumar, A. J. Parameswaran
We compute the Harder-Narasimhan filtration of vector bundles for certain finite morphisms and in some other cases.
Virtual global generation in higher dimensions
Indranil Biswas, Manish Kumar, A. J. Parameswaran
The notion of virtual global generation (VGG) for a vector bundle has multiple possible generalization from the case of curves to higher dimensional normal projective varieties. We…
On the equivariant vector bundles on
Indranil Biswas, Manish Kumar, A. J. Parameswaran
Let be a subgroup of (respectively, ) such that the Zariski closure in (respectively, ${\rm SL}(2,\math…
Isomorphism of étale fundamental groups lifts to isomorphism of stratified fundamental group
Indranil Biswas, Manish Kumar, A. J. Parameswaran
It is shown that if a finite generically smooth morphism of smooth projective varieties induces an isomorphism of the étale fundamental groups, then…
Direct image of structure sheaf and parabolic stability
Indranil Biswas, Manish Kumar, A. J. Parameswaran
Let be a dominant generically smooth morphism between irreducible smooth projective curves over an algebraically closed field such that ${\rm Char}(k)> \t…
Characterization of genuine ramification using formal orbifolds
Indranil Biswas, Manish Kumar, A. J. Parameswaran
We give a characterization of genuinely ramified maps of formal orbifolds in the Tannakian framework. In particular we show that a morphism is genuinely ramified if and only if the…
Pushforward of structure sheaf and virtual global generation
Indranil Biswas, Manish Kumar, A. J. Parameswaran
Let be a generically smooth morphism between irreducible smooth projective curves over an algebraically closed field of arbitrary characteristic. We prove that t…
Genuinely ramified maps and monodromy
Indranil Biswas, Manish Kumar, A. J. Parameswaran
For any genuinely ramified morphism between irreducible smooth projective curves we prove that is connected…
Ramified covering maps of singular curves and stability of pulled back bundles
Indranil Biswas, Manish Kumar, A. J. Parameswaran
Let be a generically smooth nonconstant morphism between irreducible projective curves, defined over an algebraically closed field, which is étale on an open…
The tame Nori fundamental group
Indranil Biswas, Manish Kumar, A. J. Parameswaran
We introduce three notion of tameness of the Nori fundamental group scheme for a normal quasiprojective variety over an algebraically closed field. It is proved that these thre…