17 мар. 2020 г. · An example when the direct image of a locally free sheaf is not locally free. Let X be a scheme over C, and Σ a smooth projective curve over C. ... When is the pushforward / direct image of a reflexive sheaf ... Pullback of locally free sheaves is locally free Stalk of the direct image of a locally free sheaf when is pushforward of flat sheaf locally free? Другие результаты с сайта math.stackexchange.com

17 нояб. 2013 г. · Is the higher direct image sheaf of a locally free sheaf over P1 locally free? ... Let f:X→P1 be a projective flat morphism, X is a projective ... ag.algebraic geometry - Local freeness of direct images pushforward of locally free sheaf is locally free? - MathOverflow When is the push-forward of the structure sheaf locally free Is the kernel of a morphism of locally free sheaves still a locally ... Другие результаты с сайта mathoverflow.net

I assume that "locally free" means "locall y free coherent" and that everything is noetherian. Then f_*(E) is flat because E is flat and f is (see ...

A finite direct sum of (finite) locally free sheaves is (finite) locally free. However, it may not be the case that an infinite direct sum of locally free ...

Therefore, under the assumptions of the theorem, the first direct image. R1π∗(E) is free if this sheaf admits a system s of k := rk(R1π∗(E)) sections which are ...

2 сент. 2013 г. · Abstract page for arXiv paper 1309.0342: On the torsion of the first direct image of a locally free sheaf.

Reflexive sheaves. Locally free sheaves, although very convenient, are too restricted for our purposes since a direct image sheaf is not necessarily locally ...

4 нояб. 2024 г. · An invertible sheaf on 𝑉 is a locally free 𝒪𝑉-module ℒ of rank 1. The tensor product of two invertible sheaves is again an invertible sheaf.

Nous étudions et décrivons explicitement le sous-faisceau de torsion T o r s ( R 1 π * ( ℰ ) ) de la première image directe R 1 π * ( ℰ ) en supposant que R 0 π ...

5 июн. 2020 г. · A sheaf of modules F over OX is said to be locally free if for every point x∈X there is an open neighbourhood U⊂X, x∈U, such that the ... Не найдено: image | Нужно включить: image