Hilbert–Kunz Functions of Cubic Curves and Surfaces Original Research Article

We determine the Hilbert–Kunz function of plane elliptic curves in odd characteristic, as well as over arbitrary fields the generalized Hilbert–Kunz functions of nodal cubic curves. Together with results of K. Pardue and P. Monsky, this completes the list of Hilbert–Kunz functions of plane cubics. Combining these results with the calculation of the (generalized) Hilbert–Kunz function of Cayleyʹs cubic surface, it follows that in each degree and over any field of positive characteristic there are curves resp. surfaces taking on the minimally possible Hilbert–Kunz multiplicity.