Perverse schobers and birational geometry
| Autor: | Vadim Schechtman, Alexey Bondal, Mikhail Kapranov |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Pure mathematics
Diagram (category theory) General Mathematics 010102 general mathematics General Physics and Astronomy Birational geometry Relative dimension 01 natural sciences Cohomology Reductive Lie algebra Minimal model program Mathematics::Algebraic Geometry Perverse sheaf Mathematics::Category Theory 0103 physical sciences 010307 mathematical physics 0101 mathematics Mathematics::Representation Theory Mathematics Resolution (algebra) |
| Zdroj: | Selecta Mathematica. 24:85-143 |
| ISSN: | 1420-9020 1022-1824 |
| DOI: | 10.1007/s00029-018-0395-1 |
| Popis: | Perverse schobers are conjectural categorical analogs of perverse sheaves. We show that such structures appear naturally in Homological Minimal Model Program which studies the effect of birational transformations such as flops, on the coherent derived categories. More precisely, the flop data are analogous to hyperbolic stalks of a perverse sheaf. In the first part of the paper we study schober-type diagrams of categories corresponding to flops of relative dimension 1, in particular we determine the categorical analogs of the (compactly supported) cohomology with coefficients in such schobers. In the second part we consider the example of a “web of flops” provided by the Grothendieck resolution associated to a reductive Lie algebra $$\mathfrak {g}$$ and study the corresponding schober-type diagram. For $$\mathfrak {g}={\mathfrak {s}\mathfrak {l}}_3$$ we relate this diagram to the classical space of complete triangles studied by Schubert, Semple and others. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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