A NOTE ON DORMANT OPERS OF RANK IN CHARACTERISTIC

2018 ◽  
Vol 235 ◽  
pp. 115-126
Author(s):  
YUICHIRO HOSHI
Keyword(s):  
Smooth Curve ◽  
Equivalence Classes ◽  
Closed Field ◽  
Algebraically Closed Field

In this paper, we prove that the set of equivalence classes of dormant opers of rank $p-1$ over a projective smooth curve of genus ${\geqslant}2$ over an algebraically closed field of characteristic $p>0$ is of cardinality one.

scholarly journals Every Curve of Genus not Greater Than Eight Lies on a K3 Surface

2008 ◽  
Vol 190 ◽  
pp. 183-197 ◽  
Author(s):  
Manabu Ide
Keyword(s):  
Smooth Curve ◽  
Ample Divisor ◽  
Closed Field ◽  
K3 Surface ◽  
Algebraically Closed Field ◽  
Double Points ◽  
Smooth Locus ◽  
Double Coverings

Let C be a smooth irreducible complete curve of genus g ≥ 2 over an algebraically closed field of characteristic 0. An ample K3 extension of C is a K3 surface with at worst rational double points which contains C in the smooth locus as an ample divisor.In this paper, we prove that all smooth curve of genera. 2 ≤ g ≤ 8 have ample K3 extensions. We use Bertini type lemmas and double coverings to construct ample K3 extensions.

scholarly journals Homology of SL2 over function fields I: Parabolic subcomplexes

2018 ◽  
Vol 2018 (739) ◽  
pp. 159-205
Author(s):  
Matthias Wendt
Keyword(s):  
Vector Bundles ◽  
Function Fields ◽  
Equivalence Classes ◽  
Isotropy Group ◽  
Closed Field ◽  
Explicit Formulas ◽  
Algebraically Closed Field ◽  
Group Homology ◽  
Equivariant Homology ◽  
Smooth Affine

Abstract The present paper studies the group homology of the groups {\operatorname{SL}_{2}(k[C])} and {\operatorname{PGL}_{2}(k[C])} , where {C=\overline{C}\setminus\{P_{1},\dots,P_{s}\}} is a smooth affine curve over an algebraically closed field k. It is well known that these groups act on a product of trees and the quotients can be described in terms of certain equivalence classes of rank two vector bundles on the curve {\overline{C}} . There is a natural subcomplex consisting of cells with suitably non-trivial isotropy group. The paper provides explicit formulas for the equivariant homology of this “parabolic subcomplex”. These formulas also describe group homology of {\operatorname{SL}_{2}(k[C])} above degree s, generalizing a result of Suslin in the case {s=1} .

scholarly journals On the Grothendieck ring of varieties

2015 ◽  
Vol 158 (3) ◽  
pp. 477-486
Author(s):  
AMIT KUBER
Keyword(s):  
Abelian Group ◽  
Free Abelian Group ◽  
Equivalence Classes ◽  
Closed Field ◽  
Associated Graded Ring ◽  
Grothendieck Ring ◽  
Algebraically Closed Field ◽  
Monoid Ring ◽  
Birational Equivalence ◽  
Multiplicative Monoid

AbstractLet K0(Vark) denote the Grothendieck ring of k-varieties over an algebraically closed field k. Larsen and Lunts asked if two k-varieties having the same class in K0(Vark) are piecewise isomorphic. Gromov asked if a birational self-map of a k-variety can be extended to a piecewise automorphism. We show that these two questions are equivalent over any algebraically closed field. If these two questions admit a positive answer, then we prove that its underlying abelian group is a free abelian group and that the associated graded ring of the Grothendieck ring is the monoid ring $\mathbb{Z}$[$\mathfrak{B}$] where $\mathfrak{B}$ denotes the multiplicative monoid of birational equivalence classes of irreducible k-varieties.

The self-intersection formula and the ‘formule-clef’

1975 ◽  
Vol 78 (1) ◽  
pp. 117-123 ◽  
Author(s):  
A. T. Lascu ◽  
D. Mumford ◽  
D. B. Scott
Keyword(s):  
Ring Homomorphism ◽  
Equivalence Classes ◽  
The Self ◽  
Group Homomorphism ◽  
Closed Field ◽  
Chow Ring ◽  
Algebraically Closed Field ◽  
Rational Equivalence ◽  
Image Position ◽  
Intersection Formula

We shall consider exclusively algebraic non-singular quasi-projective irreducible varieties over an algebraically closed field. If V is such a variety will be the Chow ring of rational equivalence classes of cycles of Vand the group homomorphism defined by any proper morphism φ: V1 → V2. Alsodenotes the ring homomorphism defined by φ.

scholarly journals On a purely inseparable analogue of the Abhyankar conjecture for affine curves

2018 ◽  
Vol 154 (8) ◽  
pp. 1633-1658
Author(s):  
Shusuke Otabe
Keyword(s):  
Fundamental Group ◽  
Positive Characteristic ◽  
Smooth Curve ◽  
Group Scheme ◽  
Partial Answer ◽  
Closed Field ◽  
Algebraically Closed Field ◽  
Affine Curves ◽  
Finite Quotients ◽  
Field Of Positive Characteristic

Let$U$be an affine smooth curve defined over an algebraically closed field of positive characteristic. The Abhyankar conjecture (proved by Raynaud and Harbater in 1994) describes the set of finite quotients of Grothendieck’s étale fundamental group$\unicode[STIX]{x1D70B}_{1}^{\acute{\text{e}}\text{t}}(U)$. In this paper, we consider a purely inseparable analogue of this problem, formulated in terms of Nori’s profinite fundamental group scheme$\unicode[STIX]{x1D70B}^{N}(U)$, and give a partial answer to it.

scholarly journals The strong simple connectedness of tame algebras with separating almost cyclic coherent Auslander–Reiten components

2021 ◽  
Author(s):  
Piotr Malicki
Keyword(s):  
Closed Field ◽  
Algebraically Closed Field ◽  
Main Application ◽  
Finite Dimensional ◽  
Simple Connectedness ◽  
Tame Algebras

AbstractWe study the strong simple connectedness of finite-dimensional tame algebras over an algebraically closed field, for which the Auslander–Reiten quiver admits a separating family of almost cyclic coherent components. As the main application we describe all analytically rigid algebras in this class.

scholarly journals On Unramified Separable Abelian p-Extensions of Function Fields I

1959 ◽  
Vol 14 ◽  
pp. 223-234 ◽  
Author(s):  
Hisasi Morikawa
Keyword(s):  
Galois Group ◽  
Function Field ◽  
Function Fields ◽  
Abelian Extension ◽  
Closed Field ◽  
Jacobian Variety ◽  
Algebraically Closed Field

Let k be an algebraically closed field of characteristic p>0. Let K/k be a function field of one variable and L/K be an unramified separable abelian extension of degree pr over K. The galois automorphisms ε1, …, εpr of L/K are naturally extended to automorphisms η(ε1), … , η(εpr) of the jacobian variety JL of L/k. If we take a svstem of p-adic coordinates on JL, we get a representation {Mp(η(εv))} of the galois group G(L/K) of L/K over p-adic integers.

scholarly journals CHARACTER CLUSTERS FOR LIE ALGEBRA MODULES OVER A FIELD OF NONZERO CHARACTERISTIC

2013 ◽  
Vol 89 (2) ◽  
pp. 234-242 ◽  
Author(s):  
DONALD W. BARNES
Keyword(s):  
Lie Algebra ◽  
Saturated Formation ◽  
Closed Field ◽  
Algebraically Closed Field ◽  
Direct Sum ◽  
Finite Dimensional ◽  
Nonzero Characteristic ◽  
Composition Factors

AbstractFor a Lie algebra $L$ over an algebraically closed field $F$ of nonzero characteristic, every finite dimensional $L$-module can be decomposed into a direct sum of submodules such that all composition factors of a summand have the same character. Using the concept of a character cluster, this result is generalised to fields which are not algebraically closed. Also, it is shown that if the soluble Lie algebra $L$ is in the saturated formation $\mathfrak{F}$ and if $V, W$ are irreducible $L$-modules with the same cluster and the $p$-operation vanishes on the centre of the $p$-envelope used, then $V, W$ are either both $\mathfrak{F}$-central or both $\mathfrak{F}$-eccentric. Clusters are used to generalise the construction of induced modules.

scholarly journals Classification of one-dimensional superattracting germs in positive characteristic

2014 ◽  
Vol 35 (7) ◽  
pp. 2242-2268 ◽  
Author(s):  
MATTEO RUGGIERO
Keyword(s):  
Positive Characteristic ◽  
Closed Field ◽  
Algebraically Closed Field ◽  
One Dimensional ◽  
Higher Dimensional ◽  
Dimensional Version

We give a classification of superattracting germs in dimension $1$ over a complete normed algebraically closed field $\mathbb{K}$ of positive characteristic up to conjugacy. In particular, we show that formal and analytic classifications coincide for these germs. We also give a higher-dimensional version of some of these results.

scholarly journals Geometric Weil representation in characteristic two

2011 ◽  
Vol 11 (2) ◽  
pp. 221-271 ◽  
Author(s):  
Alain Genestier ◽  
Sergey Lysenko
Keyword(s):  
Weil Representation ◽  
Closed Field ◽  
Triangulated Category ◽  
Algebraically Closed Field ◽  
Witt Vectors ◽  
Suitable Sense ◽  
Characteristic Two ◽  
Greenberg Realization ◽  
Geometric Analogue

AbstractLet k be an algebraically closed field of characteristic two. Let R be the ring of Witt vectors of length two over k. We construct a group stack Ĝ over k, the metaplectic extension of the Greenberg realization of $\operatorname{\mathbb{S}p}_{2n}(R)$. We also construct a geometric analogue of the Weil representation of Ĝ, this is a triangulated category on which Ĝ acts by functors. This triangulated category and the action are geometric in a suitable sense.

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