A priori bounds of Castelnuovo type for cohomological Hilbert functions.
We describe a number of classes in the Picard group of spin moduli space and determine the relations they satisfy; as an application we show that the Picard group in question contains 4-torsion elements.
Given a smooth proper dg algebra , a perfect dg -module and an endomorphism of , we define the Hochschild class of the pair with values in the Hochschild homology of the algebra . Our main result is a Riemann-Roch type formula involving the convolution of two such Hochschild classes.
The note is about a connection between Seshadri constants and packing constants and presents another proof of Lazarsfeld's result from [Math. Res. Lett. 3 (1996), 439-447].