Аннотация:
We give an orbifold Riemann–Roch formula in closed form for the Hilbert series of a quasismooth polarized $n$-fold $(X,D)$, under the assumption that $X$ is projectively Gorenstein with only isolated orbifold points. Our formula is a sum of parts each of which is integral and Gorenstein symmetric of the same canonical weight; the orbifold parts
are called ice cream functions. This form of the Hilbert series is particularly useful for computer algebra, and we illustrate it on examples of $\mathrm{K3}$ surfaces and Calabi–Yau 3-folds.
These results apply also with higher dimensional orbifold strata (see [1] and [2]), although the precise
statements are considerably trickier. We expect to return to this in future publications.
Bibliography: 22 titles.
Partially funded by Korean Government WCU Grant R33-2008-000-10101-0. S.~Zhou was supported by a University of Warwick Postgraduate Research Studentship.
Поступило в редакцию: 02.07.2012 Исправленный вариант: 22.08.2012
Образец цитирования:
A. Buckley, M. Reid, S. Zhou, “Ice cream and orbifold Riemann–Roch”, Изв. РАН. Сер. матем., 77:3 (2013), 29–54; Izv. Math., 77:3 (2013), 461–486