Weighted projective planes and threefold singularities
This thesis studies weighted projective planes and their connection to threefold singularities. In particular, we study the Veronese subring Sโ๐ฅ of the ring S associated with the weighted projective plane ๐ for choices of โ๐ฅ in the grading group ๐. We show that there exists a projective, birational map Tโ๐ฅ โถ Spec Sโ๐ฅ under mild restrictions on โ๐ฅ. We then show that when โ๐ฅ = -โฯ, the dualising element, this map is a blow-up. In the toric setting, we show that in certain situations the singularities of S-โฯ can be identified with the familiar cyclic quotient singularities and the map T-โฯ โถ Spec S-โฯ is a weighted blow-up. In particular, it is a crepant map. We also construct a tilting object on T-โฯ in this setting. Away from the toric setting, we are able to construct tilting objects in some instances and we study some examples in depth to construct a full resolution and identify noncommutative resolutions of these singularities.
http://theses.gla.ac.uk/83074/10.5525/gla.thesis.83074
https://theses.gla.ac.uk/83074/3/2022KelleherPhD.pdf