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Related papers: Class field theory for curves over local fields

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Inside the moduli space of curves of genus 2 with 2 marked points we consider the loci of curves admitting a map to P^1 of degree d totally ramified over the two marked points, for d>= 2. Such loci have codimension two. We compute the class…

Algebraic Geometry · Mathematics 2014-10-30 Nicola Tarasca

In this expository article, we outline a basic theory of group (co)homology and prove a cohomological formulation of the Local Reciprocity Law: $${\rm Gal}(L/K)^{\rm ab} \cong H_T^{-2}({\rm Gal}(L/K),\mathbb{Z}) \cong H_T^{0}({\rm…

Number Theory · Mathematics 2024-05-27 Uzu Lim

We construct an analog of the Hodge theory on complex manifolds on tropical curves. We use the analytical approach to the problem, it is based on language of tropical differential forms and methods of $L^2-$cohomologies.

Algebraic Geometry · Mathematics 2023-04-11 Yury Eliyashev

We study for rationally connected varieties $X$ the group of degree 2 integral homology classes on $X$ modulo those which are algebraic. We show that the Tate conjecture for divisor classes on surfaces defined over finite fields implies…

Algebraic Geometry · Mathematics 2012-01-17 Claire Voisin

In this mostly expository paper we review several known results about the cohomology of moduli spaces of smooth and stable curves, focusing in particular on low degree cohomology. We also give a new proof of Harer's theorem describing the…

Algebraic Geometry · Mathematics 2008-12-19 Enrico Arbarello , Maurizio Cornalba

Given a morphism between complex projective varieties, we make several conjectures on the relations between the set of pseudo-effective (co)homology classes which are annihilated by pushforward and the set of classes of varieties contracted…

Algebraic Geometry · Mathematics 2013-03-04 O. Debarre , Z. Jiang , C. Voisin

We establish several compatibility results between residue maps in \'etale and Galois cohomology that arise naturally in the analysis of smooth affine algebraic curves having good reduction over discretely valued fields. These results are…

Number Theory · Mathematics 2018-02-07 Igor A. Rapinchuk

We prove an equivariant Riemann-Roch formula for divisors on algebraic curves over perfect fields. By reduction to the known case of curves over algebraically closed fields, we first show a preliminary formula with coefficients in Q. We…

Algebraic Geometry · Mathematics 2008-04-11 Helena B. Fischbacher-Weitz , Bernhard Köck

We present an algorithm which, given a connected smooth projective curve $X$ over an algebraically closed field of characteristic $p>0$ and its Hasse--Witt matrix, as well as a positive integer $n$, computes all \'etale Galois covers of $X$…

Number Theory · Mathematics 2025-09-16 Christophe Levrat , Rubén Muñoz--Bertrand

We establish for smooth projective real curves the equivalent of the classical Clifford inequality known for complex curves. We also study the cases when equality holds.

Algebraic Geometry · Mathematics 2007-05-23 Jean-Philippe Monnier

We show that a Hodge class of a complex smooth projective hypersurface is an analytic logarithmic De Rham class. On the other hand we show that for a complex smooth projective variety an analytic logarithmic De Rham class of of type $(d,d)$…

Algebraic Geometry · Mathematics 2025-10-17 Johann Bouali

We introduce a new cohomology-theoretic method for classifying generic immersed curves in closed compact surfaces by using Gauss codes. This subsumes a result of J.S. Carter on classifying immersed curves in oriented compact surfaces, and…

Geometric Topology · Mathematics 2012-09-20 Mario O. Bourgoin

Two fields are Witt equivalent if their Witt rings of symmetric bilinear forms are isomorphic. Witt equivalent fields can be understood to be fields having the same quadratic form theory. The behavior of finite fields, local fields, global…

Rings and Algebras · Mathematics 2016-04-26 Paweł Gładki , Murray Marshall

Over a global field (number field or function field of a curve over a finite field), theorems for the Galois cohomology of algebraic groups have long been known. For $F$ the function field of a curve over the formal series field…

Number Theory · Mathematics 2023-12-12 Dylon Chow

We show that every smooth projective curve over a finite field k admits a finite tame morphism to the projective line over k. Furthermore, we construct a curve with no such map when k is an infinite perfect field of characteristic two. Our…

Algebraic Geometry · Mathematics 2021-10-05 Kiran S. Kedlaya , Daniel Litt , Jakub Witaszek

In this paper we prove global class field theory using a purely geometric result. We first write in detail Deligne's proof to the unramified case of class field theory, including defining the required objects for the proof. Then we…

Algebraic Geometry · Mathematics 2015-07-02 Avichai Tendler

In this article, we prove the Hodge conjecture for a desingularization of the moduli space of rank 2, semi-stable, torsion-free sheaves with fixed odd degree determinant over a very general irreducible nodal curve of genus at least 2. We…

Algebraic Geometry · Mathematics 2022-05-10 Ananyo Dan , Inder Kaur

We use Hodge theory to prove a new upper bound on the ranks of Mordell-Weil groups for elliptic curves over function fields after regular geometrically Galois extensions of the base field, improving on previous results of Silverman and…

Algebraic Geometry · Mathematics 2014-01-07 Ambrus Pal

Let U be a smooth quasi-projective variety over a field k that is finite, the algebraic closure of a finite field or algebraically closed of characteristic 0. Let X be a suitable projective compactification of U, and D an effective divisor…

Algebraic Geometry · Mathematics 2023-11-08 Henrik Russell

In all possible cases, we prove that local embeddings between two curve complexes whose complexities do not increase from domain to codomain are induced by surface homeomorphism. This is our first main result. From this we can deduce our…

Geometric Topology · Mathematics 2007-05-23 Kenneth J. Shackleton