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For a valuation ring $V$, a smooth $V$-algebra $A$, and a reductive $V$-group scheme $G$ satisfying a certain natural isotropicity condition, we prove that every Nisnevich $G$-torsor on $\mathbb{A}^N_A$ descends to a $G$-torsor on $A$. As a…

Algebraic Geometry · Mathematics 2025-05-09 Ning Guo , Fei Liu

This paper establishes the equivalence of the Aubin property and the strong regularity for generalized equations over $C^2$-cone reducible sets. This result resolves a long-standing question in variational analysis and extends the…

Optimization and Control · Mathematics 2025-10-14 Jiaming Ma , Defeng Sun

Let $A$ and $B$ be abelian varieties defined over the function field $k(S)$ of a smooth algebraic variety $S/k.$ We establish criteria, in terms of restriction maps to subvarieties of $S,$ for existence of various important classes of…

Algebraic Geometry · Mathematics 2023-04-12 Wojciech Gajda , Sebastian Petersen

We formulate and study a torsion analogue of the weight-monodromy conjecture for a proper smooth scheme over a non-archimedean local field. We prove it for proper smooth schemes over equal characteristic non-archimedean local fields,…

Number Theory · Mathematics 2020-08-28 Kazuhiro Ito

We prove, for quasicompact separated schemes over ground fields, that Cech cohomology coincides with sheaf cohomology with respect to the Nisnevich topology. This is a partial generalization of Artin's result that for noetherian schemes…

Algebraic Geometry · Mathematics 2017-06-14 Stefan Schröer

We prove that N\'eron models of jacobians of generically-smooth nodal curves over bases of arbitrary dimension are quasi-compact (hence of finite type) whenever they exist. We give a simple application to the orders of torsion subgroups of…

Algebraic Geometry · Mathematics 2016-04-08 David Holmes

We extend the notion of absolute subsets of Betti moduli spaces of smooth algebraic varieties to the case of normal varieties. As a consequence we prove that twisted cohomology jump loci in rank one over a normal variety are a finite union…

Algebraic Geometry · Mathematics 2022-02-15 Leonardo A. Lerer

In his 1979 paper Trotman proves, using the techniques of the Thom transversality theorem, that under some conditions on the dimensions of the manifolds under consideration, openness of the set of maps transverse to a stratification in the…

Differential Geometry · Mathematics 2015-04-30 Saurabh Trivedi

A theorem of Manin and Drinfeld states that any divisor of degree $0$ on the cusps of a modular curve is torsion in the Jacobian. An elegant proof of this result was provided by Elkik using mixed Hodge theory. Rohrlich proved a…

Algebraic Geometry · Mathematics 2026-03-03 Ramesh Sreekantan

We derive a Serre presentation of distribution algebras of loop groups in characteristic $p$ and apply it to give a new proof of the normality of Schubert varieties inside parahoric affine Grassmannians, for all connected reductive groups…

Representation Theory · Mathematics 2023-12-29 João Lourenço

Let Z be an affine algebraic variety and ED(Z)= max(2 dim Z+1, dim TZ). Let X be a smooth algebraic variety isomorphic to a semi-simple linear algebraic group whose Lie algebra is a sum of special linear Lie algebras. We show that if dim X…

Algebraic Geometry · Mathematics 2022-07-21 Shulim Kaliman

For a smooth projective variety X over an arbitrary field k, we discuss the surjectivity of the Albanese map from the Chow group of zero-cycles of degree zero on X to the group of rational points of the Albanese variety of X. Over…

Algebraic Geometry · Mathematics 2025-06-10 Jean-Louis Colliot-Thélène

We describe algebraically defined cohomological and homological Albanese and Picard 1-motives (or mixed motives) of any algebraic variety in characteristic zero, generalizing the classical Albanese and Picard varieties. We compute Hodge,…

Algebraic Geometry · Mathematics 2007-05-23 L. Barbieri-Viale , V. Srinivas

We prove a general form of the regularity theorem for uniformity norms, and deduce an inverse theorem for these norms which holds for a class of compact nilspaces including all compact abelian groups, and also nilmanifolds; in particular we…

Combinatorics · Mathematics 2022-03-15 Pablo Candela , Balázs Szegedy

For a quasi-projective scheme $X$ admitting a smooth compactification over a local field of residue characteristic $p > 0$, we construct a continuous reciprocity homomorphism from a tame class group to the abelian tame etale fundamental…

Algebraic Geometry · Mathematics 2026-01-21 Rahul Gupta , Amalendu Krishna , Jitendra Rathore

We introduce three notion of tameness of the Nori fundamental group scheme for a normal quasiprojective variety $X$ over an algebraically closed field. It is proved that these three notions agree if $X$ admits a smooth completion with…

Algebraic Geometry · Mathematics 2025-06-16 Indranil Biswas , Manish Kumar , A. J. Parameswaran

In this paper we show that Mergelyan's theorem holds for maps from open Riemann surfaces to Oka manifolds. This is used to prove the analogue of Arakelian's theorem on uniform approximation of holomorphic maps from closed subsets of the…

Complex Variables · Mathematics 2020-04-16 Franc Forstneric

We show the existence of a regular universal quotient as a smooth commutative algebraic group of the Chow group of 0-cycles on a projective reduced variety, and give over the field of complex numbers an analytic description of it. This…

alg-geom · Mathematics 2007-05-23 Hélène Esnault , V. Srinivas , Eckart Viehweg

Let $U$ be a smooth and connected curve over an algebraically closed field of positive characteristic, with smooth compactification $X$. We generalize classical Geometric Class Field theory to provide a classification of fppf $G$-torsors…

Algebraic Geometry · Mathematics 2026-03-20 Bryden Cais , Shusuke Otabe

We prove a finiteness theorem for the first flat cohomology group of finite flat group schemes over integral normal proper varieties over finite fields. As a consequence, we can prove the invariance of the finiteness of the Tate-Shafarevich…

Number Theory · Mathematics 2022-03-14 Timo Keller