English

Canonical tilting relative generators

Algebraic Geometry 2017-09-19 v4

Abstract

Given a relatively projective birational morphism f ⁣:XYf\colon X\to Y of smooth algebraic spaces with dimension of fibers bounded by 1, we construct tilting relative (over YY) generators TX,fT_{X,f} and SX,fS_{X,f} in Db(X)\mathcal{D}^b(X). We develop a piece of general theory of strict admissible lattice filtrations in triangulated categories and show that Db(X)\mathcal{D}^b(X) has such a filtration L\mathcal{L} where the lattice is the set of all birational decompositions f ⁣:XgZhYf \colon X \xrightarrow{g} Z \xrightarrow{h} Y with smooth ZZ. The tt-structures related to TX,fT_{X,f} and SX,fS_{X,f} are proved to be glued via filtrations left and right dual to L\mathcal{L}. We realise all such ZZ as the fine moduli spaces of simple quotients of OX\mathcal{O}_X in the heart of the tt-structure for which SX,gS_{X,g} is a relative projective generator over YY. This implements the program of interpreting relevant smooth contractions of XX in terms of a suitable system of tt-structures on Db(X)\mathcal{D}^b(X).

Keywords

Cite

@article{arxiv.1701.08834,
  title  = {Canonical tilting relative generators},
  author = {Agnieszka Bodzenta and Alexey Bondal},
  journal= {arXiv preprint arXiv:1701.08834},
  year   = {2017}
}

Comments

43 pages

R2 v1 2026-06-22T18:04:39.250Z