The moduli stack MX(E8) of principal E8-bundles over a smooth projective curve X carries a natural divisor ∆. We study the pull-back of the divisor ∆ to the moduli stack MX(P ), where P is a semi-simple and simply connected group such that its Lie algebra Lie(P ) is a maximal conformal subalgebra of Lie(E8). We show that the divisor ∆ induces “Strange Duality”-type isomorphisms between the Verl...

We present an algorithm for reducing a divisor on a hyperelliptic curve of arbitrary genus over any finite field. Our method is an adaptation of a procedure for reducing ideals in quadratic number fields due to Jacobson, Sawilla and Williams, and shares common elements with both the Cantor and the NUCOMP algorithms for divisor arithmetic. Our technique is especially suitable for the rapid reduc...

When the seats in a parliamentary body are to be allocated proportionally to some given weights, such as vote counts or population data, divisor methods form a prime class to carry out the apportionment. We present a new characterization of divisor methods, via primal and dual optimization problems. The primal goal function is a cumulative product of the discontinuity points of the rounding rul...

In this article we prove that for any complete toric variety, and for any Cartier divisor, the ring of global sections of multiples of the line bundle associated to the divisor is finitely generated.

Throughout this paper, a curve will be an irreducible nonsingular onedimensional projective variety over an algebraically closed field F of characteristic not 2. In Chapter 1 of his beautiful survey [7], Mumford undertakes to exhibit “every curve”. The nonhyperelliptic curves are described by the equations of their canonical embeddings [8, 91, but the hyperelliptic curves are given only as rami...

A finite group G is said to be a POS-group if for each x in G the cardinality of the set {y in G | o(y) = o(x)} is a divisor of the order of G. In this paper we study the structure of POS-groups with some cyclic Sylow subgroups.

Hara [Ha3] and Smith [Sm2] independently proved that in a normal Q-Gorenstein ring of characteristic p ≫ 0, the test ideal coincides with the multiplier ideal associated to the trivial divisor. We extend this result for a pair (R,∆) of a normal ring R and an effective Q-Weil divisor ∆ on SpecR. As a corollary, we obtain the equivalence of strongly F-regular pairs and klt pairs.