Speaker
Shinnosuke Okawa
Description
Ekedahl constructed a family of smooth projective surfaces in characteristic 2 with ample canonical bundles which are purely inseparable finite covers of the projective plane. We prove that the derived category of such a surface admits an exceptional collection of line bundles of length 3. A remarkable feature is that the semiorthogonal complement of the collection has 2-torsion Grothendieck group whereas its Hochschild homology is non-trivial, which suggests that the definition of quasi-phantom categories should be modified in positive characteristics. This is a joint work with Koshiro Murai.
