English
Related papers

Related papers: Some Extensions of Witt's Theorem

200 papers

This is an account of the algebraic geometry of Witt vectors and arithmetic jet spaces. The usual, "p-typical" Witt vectors of p-adic schemes of finite type are already reasonably well understood. The main point here is to generalize this…

Algebraic Geometry · Mathematics 2015-12-15 James Borger

Consider a complete flag $\{0\} = C_0 < C_1 < \cdots < C_n = \mathbb{F}^n$ of one-point AG codes of length $n$ over the finite field $\mathbb{F}$. The codes are defined by evaluating functions with poles at a given point $Q$ in points…

Information Theory · Computer Science 2019-06-26 Maria Bras-Amorós , Iwan Duursma , Euijin Hong

We extend Lusternik-Schnirelmann theory to pairs $(f, \phi)$, where $\phi$ is a homotopy equivalence of a space $X$, $f$ is a function on $X$ which decreases along $\phi$ and $(f, \phi)$ satisfies a discrete analog of the Palais-Smale…

Dynamical Systems · Mathematics 2007-05-23 Yu. B. Rudyak , F. Schlenk

We show that a map between projection lattices of semi-finite von Neumann algebras can be extended to a Jordan $*$-homomorphism between the von Neumann algebras if this map is defined in terms of the support projections of images (under the…

Operator Algebras · Mathematics 2018-11-12 Pierre de Jager , Jurie Conradie

In this paper we show that topological subgroupoids of Lie groupoids, under special circumstances are Lie subgroupoids. Giving an example, we indicate that having the same topological dimension is a necessary condition for topological…

Differential Geometry · Mathematics 2018-03-15 A. R. Armakan , M. R. Farhangdoost , F. Gorlizkhatami , T. Nasirzadeh

Given a countable group $G$ and two subshifts $X$ and $Y$ over $G$, a continuous, shift-commuting map $\phi : X \to Y$ is called a homomorphism. Our main result states that if every finitely generated subgroup of $G$ has polynomial growth,…

Dynamical Systems · Mathematics 2025-09-10 Robert Bland , Kevin McGoff

In this paper, we give a necessary and sufficient condition that discrete Morse functions on a digraph can be extended to be Morse functions on its transitive closure, from this we can extend the Morse theory to digraphs by using…

Combinatorics · Mathematics 2021-11-16 Yong Lin , Chong Wang , Shing-Tung Yau

For Kummer extensions $y^m=f(x)$, we discuss conditions for an integer be a Weierstrass gap at a place $P$. In the case of totally ramified places, the conditions will be necessary and sufficient. As a consequence, we extend independent…

Algebraic Geometry · Mathematics 2015-11-09 Miriam Abdon , Herivelto Borges , Luciane Quoos

Under integral restrictions on dilatations, it is proved existence theorems for the degenerate Beltrami equations with two characteristics and, in particular, to the Beltrami equations of the second type that play a great role in many…

Complex Variables · Mathematics 2010-02-18 B. Bojarski , V. Gutlyanskii , V. Ryazanov

We introduce the notion of \emph{topo-symmetric extensions} of topological groups, a new generalization of classical group extensions that incorporates both topological and symmetry constraints. We define morphisms between such extensions,…

General Mathematics · Mathematics 2025-10-02 Es-said En-naoui

We introduce the new algebraic property of Weyl compatibility for symmetric tensors and vectors. It is strictly related to Riemann compatibility, which generalizes the Codazzi condition while preserving much of its geometric implications.…

Mathematical Physics · Physics 2016-03-10 Carlo A. Mantica , Luca G. Molinari

We study expanding maps and shrinking maps of subvarieties of Grassmann varieties in arbitrary characteristic. The shrinking map was studied independently by Landsberg and Piontkowski in order to characterize Gauss images. To develop their…

Algebraic Geometry · Mathematics 2014-02-06 Katsuhisa Furukawa

Using ``Tate's algorithm,'' we identify loci in the moduli of F-theory compactifications corresponding to enhanced gauge symmetry. We apply this to test the proposed F-theory/heterotic dualities in six dimensions. We recover the…

High Energy Physics - Theory · Physics 2009-10-07 M. Bershadsky , K. Intriligator , S. Kachru , D. R. Morrison , V. Sadov , C. Vafa

The criteria for determining graph isomorphism are crucial for solving graph isomorphism problems. The necessary condition is that two isomorphic graphs possess invariants, but their function can only be used to filtrate and subdivide…

Graphics · Computer Science 2025-08-19 Chuanfu Hu , Aimin Hou

The classical Ehresmann-Bruhat order describes the possible degenerations of a pair of flags in a finite-dimensional vector space V; or, equivalently, the closure of an orbit of the group GL(V) acting on the direct product of two full flag…

Representation Theory · Mathematics 2007-05-23 Evgeny Smirnov

The notion of the ultrametrics can be considered as a zero-dimensional analogue of ordinary metrics, and it is expected to prove ultrametric versions of theorems on metric spaces. In this paper, we provide ultrametric versions of the…

Metric Geometry · Mathematics 2021-03-12 Yoshito Ishiki

We adapt the definition of the Vietoris map to the framework of finite topological spaces and we prove some coincidence theorems. From them, we deduce a Lefschetz fixed point theorem for multivalued maps that improves recent results in the…

Dynamical Systems · Mathematics 2020-10-27 Pedro J. Chocano , Manuel A. Morón , Francisco R. Ruiz del Portal

Two fields are Witt equivalent if, roughly speaking, they have the same quadratic form theory. Formally, that is to say that their Witt rings of symmetric bilinear forms are isomorphic. This equivalence is well understood only in a few…

Rings and Algebras · Mathematics 2016-09-08 Paweł Gładki , Murray Marshall

A simple local proof of Noether's Second Theorem is given. This proof immediately leads to a generalization of the theorem, yielding conservation laws and/or explicit relationships between the Euler--Lagrange equations of any variational…

Mathematical Physics · Physics 2015-05-27 Peter E. Hydon , Elizabeth L. Mansfield

This paper contains two main results. The first is the existence of an equivariant Weil-Petersson geodesic in Teichmueller space for any choice of pseudo-Anosov mapping class. As a consequence one obtains a classification of the elements of…

Differential Geometry · Mathematics 2007-05-23 Georgios Daskalopoulos , Richard Wentworth