Divisor

About: Divisor is a research topic. Over the lifetime, 2462 publications have been published within this topic receiving 21394 citations. The topic is also known as: factor & submultiple.

Chern classes of free hypersurface arrangements

Abstract: The Chern class of the sheaf of logarithmic derivations along a simple normal crossing divisor equals the Chern-Schwartz-MacPherson class of the complement of the divisor. We extend this equality to more general divisors, which are locally analytically isomorphic to free hyperplane arrangements.

The average prime divisor of an integer in short intervals

Abstract: and as usual co(n) is the number of distinct prime factors of n, f2(n) is the total number of prime factors of n, f II n means that p~ (p prime) exactly divides n. It was shown in [1] that, for each fixed natural number m, there exist computable constants el, e z, ..., era, fa,f2 ..... fro, 0 2). These questions were considered in a general setting by De Koninck and Mercier [2], where under suitable conditions asymptotic relations of the form (1.3) Y~ f(P(n)) = (1 + o(1)) Z f(n) (x ~co)

Ordered Factorizations with $k$ Factors

Abstract: We give an overview of combinatoric properties of the number of ordered $k$-factorizations $f_k(n,l)$ of an integer, where every factor is greater or equal to $l$. We show that for a large number $k$ of factors, the value of the cumulative sum $F_k(x,l)=\sum olimits_{n\leq x} f_k(n,l)$ is a polynomial in $\lfloor \log_l x \rfloor$ and give explicit expressions for the degree and the coefficients of this polynomial. An average order of the number of ordered factorizations for a fixed number $k$ of factors greater or equal to 2 is derived from known results of the divisor problem.

On the symplectic structures on moduli space of stable sheaves over a K3 or abelian surface and on Hilbert scheme of points.

Abstract: Fix a smooth very ample curve C on a K3 or abelian surface X. Let $ \mathcal{M} $ denote the moduli space of pairs of the form (F, s), where F is a stable sheaf over X whose Hilbert polynomial coincides with that of the direct image, by the inclusion map of C in X, of a line bundle of degree d over C, and s is a nonzero section of F. Assume d to be sufficiently large such that F has a nonzero section. The pullback of the Mukai symplectic form on moduli spaces of stable sheaves over X is a holomorphic 2-form on $ \mathcal{M} $. On the other hand, $ \mathcal{M} $ has a map to a Hilbert scheme parametrizing 0-dimensional subschemes of X that sends (F, s) to the divisor, defined by s, on the curve defined by the support of F. We prove that the above 2-form on $ \mathcal{M} $ coincides with the pullback of the symplectic form on the Hilbert scheme.