The divisor class group of splittable Zariski surfaces

2018 ◽  
Vol 17 (08) ◽  
pp. 1850150 ◽  
Author(s):  
Jeffrey Lang

Let [Formula: see text] be an algebraically closed field of characteristic [Formula: see text] and [Formula: see text]. Let [Formula: see text] be a normal variety defined by the equation [Formula: see text]. If [Formula: see text] is a product of [Formula: see text] linear factors in [Formula: see text], not necessarily homogeneous, where [Formula: see text] equals the degree of [Formula: see text], we say that [Formula: see text] is splittable. In this paper, we calculate the group of Weil divisors of a splittable [Formula: see text] for a generic [Formula: see text] when the characteristic of [Formula: see text] equals [Formula: see text]. In the process, we describe a general approach to studying class groups of splittable [Formula: see text] that we believe should yield results when [Formula: see text].

2013 ◽  
Vol 212 ◽  
pp. 139-157
Author(s):  
Kazuhiko Kurano

AbstractWe describe the divisor class group and the graded canonical module of the multisection ringT(X;D1,…,Ds) for a normal projective varietyXand Weil divisorsD1,…,DsonXunder a mild condition. In the proof, we use the theory of Krull domain and the equivariant twisted inverse functor.


1976 ◽  
Vol 28 (3) ◽  
pp. 659-664 ◽  
Author(s):  
Andy R. Magid

Let G be a n affine algebraic group over the algebraically closed field k, and let V be an affine, normal algebraic variety over k on which G acts. Suppose that the ring of invariants k [F]G is finitely generated over k, and let W be the affine variety with k[W] = k[V]G. The purpose of this paper is to show that the induced homomorphism from the étale fundamental group of V to that of W is surjective, and to examine the consequences of this observation in terms of the relations between the Picard and divisor class groups of k[V] and k[W],


2013 ◽  
Vol 212 ◽  
pp. 139-157 ◽  
Author(s):  
Kazuhiko Kurano

AbstractWe describe the divisor class group and the graded canonical module of the multisection ring T (X;D1,…, Ds) for a normal projective variety X and Weil divisors D1,…, Ds on X under a mild condition. In the proof, we use the theory of Krull domain and the equivariant twisted inverse functor.


1994 ◽  
Vol 96 (2) ◽  
pp. 97-112 ◽  
Author(s):  
David F. Anderson ◽  
Scott T. Chapman ◽  
William W. Smith

2010 ◽  
Vol 3 (0) ◽  
pp. 1-14
Author(s):  
Rafael Hernández ◽  
Daniel Ortega

2003 ◽  
Vol 46 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Scott T. Chapman ◽  
William W. Smith

AbstractWe consider the factorization properties of block monoids on $\mathbb{Z}_n$ determined by subsets of the form $S_a=\{\bar{1},\bar{a}\}$. We denote such a block monoid by $\mathcal{B}_a(n)$. In §2, we provide a method based on the division algorithm for determining the irreducible elements of $\mathcal{B}_a(n)$. Section 3 offers a method to determine the elasticity of $\mathcal{B}_a(n)$ based solely on the cross number. Section 4 applies the results of §3 to investigate the complete set of elasticities of Krull monoids with divisor class group $\mathbb{Z}_n$.AMS 2000 Mathematics subject classification: Primary 20M14; 20D60; 13F05


Author(s):  
Thomas Polstra

Abstract It is shown that for any local strongly $F$-regular ring there exists natural number $e_0$ so that if $M$ is any finitely generated maximal Cohen–Macaulay module, then the pushforward of $M$ under the $e_0$th iterate of the Frobenius endomorphism contains a free summand. Consequently, the torsion subgroup of the divisor class group of a local strongly $F$-regular ring is finite.


2009 ◽  
Vol 322 (9) ◽  
pp. 3373-3391 ◽  
Author(s):  
G.V. Ravindra ◽  
V. Srinivas

1992 ◽  
Vol 111 (2) ◽  
pp. 267-272
Author(s):  
Hurit nsiper

Given a smooth projective surface X over an algebraically closed field k and a modulus (an effective divisor) m on X, one defines the idle class group Cm(X) of X with modulus m (see 1, chapter III, section 4). The corresponding generalized Albanese variety Gum and the generalized Albanese map um:X|m|Gum have the following universal mapping property (2): if :XG is a rational map into a commutative algebraic group which induces a homomorphism Cm(X)G(k) (1, chapter III, proposition 1), then factors uniquely through um.


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