Videolibrary
RUS  ENG    JOURNALS   PEOPLE   ORGANISATIONS   CONFERENCES   SEMINARS   VIDEO LIBRARY   PACKAGE AMSBIB  
Video Library
Archive
Most viewed videos

Search
RSS
New in collection






Conference in honour of Alexey Bondal's 60th birthday
December 17, 2021 12:15–13:15, Moscow, Zoom
 


Weakly localising subcategories of coherent sheaves and isomorphisms in codimension two

A. Bodzenta

University of Warsaw
Video records:
MP4 1,530.6 Mb

Number of views:
This page:198
Video files:61



Abstract: I will consider a weakly localising Serre subcategory $B$ in an abelian category $A$, i.e. a Serre subcategory such that the quotient $A/B$ admits a torsion pair with the torsion-free part equivalent to the category $E$ of $B$-closed objects. I will give sufficient conditions for $B$ to be weakly localising in terms of torsion-tilting chains in $A$. I will also argue that $T$-consistent pairs of t-structures of amplitude 2 are equivalent to (strongly) torsion-tilting chains. Given a scheme $X$ of dimension $n$, the derived category $\mathrm{D}(X)$ admits a $T$-consistent pair of t-structures of amplitude $n$ which yields a pair of amplitude 2. As a result, the category $\mathrm{Coh}_2(X)$ of sheaves supported in codimension 2 is weakly localising. I will prove that, under additional assumptions on $X$, the additive category $E_2(X)$ of locally $\mathrm{Coh}_2(X)$-closed objects allows us to reconstruct $X$ up to an isomorphism outside of codimension 2. For a normal surface $X$ I will construct its final model $X'$ from the additive category $E_2(X)$. I will argue that $X$ admits an open embedding into $X'$ with complement of codimension two and I will give conditions under which $X$ is isomorphic to $X'$. This is based on a joint work with A. Bondal.

Language: English
 
  Contact us:
 Terms of Use  Registration to the website  Logotypes © Steklov Mathematical Institute RAS, 2024