English
Related papers

Related papers: Almost positively closed models

200 papers

Basic definitions and properties of nearly associative algebras are described. Nearly associative algebras are proved to be Lie-admissible algebras. Two-dimensional nearly associative algebras are classified, and its main classes are…

Rings and Algebras · Mathematics 2021-02-01 Mafoya Landry Dassoundo , Sergei Silvestrov

This note is concerned in so called harmonic complex structures introduced by the author previously. I will recall some previous results and emphasize the motivation: Provide an attempt to a fundamental problem in geometry--determining the…

Differential Geometry · Mathematics 2016-10-27 Jianming Wan

We prove a version of a small index property theorem for strong amalgamation classes. Our result builds on an earlier theorem by Lascar and Shelah (in their case, for saturated models of uncountable first-order theories). We then study…

Logic · Mathematics 2017-10-10 Zaniar Ghadernezhad , Andrés Villaveces

This article focuses on approximately prime rings and approximately prime ideals in proximal relator spaces, especially in descriptive proximity spaces. In particular, we define some binary operations, including the product of two…

Rings and Algebras · Mathematics 2025-04-08 Maram Almahariq , James Francis Peters , Tane Vergili

We investigate a slight weakening of the classical property of strong approximation, which we call almost strong approximation, for connected reductive algebraic groups over global fields with respect to special sets of valuations. While…

Algebraic Geometry · Mathematics 2026-01-13 Andrei S. Rapinchuk , Wojciech Tralle

We study valued fields equipped with an automorphism. We prove that all of them have an extension admitting an equivariant cross-section of the valuation. In residual characteristic zero, and in the presence of such a cross-section, we show…

Logic · Mathematics 2025-12-18 Jan Dobrowolski , Francesco Gallinaro , Rosario Mennuni

We extend the relation between quasi-modular forms and modular forms to a wider class of functions. We then relate both forms to vector-valued modular forms with symmetric power representations, and prove a general structure theorem for…

Number Theory · Mathematics 2020-08-12 Shaul Zemel

In this paper, we introduce a strong property $(A)$ and we study the transfer of property $(A)$ and strong property $(A)$ in trivial ring extensions and amalgamated duplication of a ring along an ideal. We also exhibit a class of rings…

Commutative Algebra · Mathematics 2009-08-11 Najib Mahdou , Aziza Rahmouni Hassani

The notion of an existentially closed model is generalised to a property of geometric morphisms between toposes. We show that important properties of existentially closed models extend to existentially closed geometric morphisms, such as…

Category Theory · Mathematics 2024-06-06 Mark Kamsma , Joshua Wrigley

We introduce a general notion of covering property, of which many classical definitions are particular instances. Notions of closure under various sorts of convergence, or, more generally, under taking kinds of accumulation points, are…

General Topology · Mathematics 2022-06-28 Paolo Lipparini

We introduce the concept of generalized almost plastic structure, and, on a pseudo-Riemannian manifold endowed with two $(1,1)$-tensor fields satisfying some compatibility conditions, we construct a family of generalized almost plastic…

Differential Geometry · Mathematics 2024-11-21 Adara M. Blaga , Antonella Nannicini

We investigate global properties of the mappings entering the description of symmetries of integrable spin and vertex models, by exploiting their nature of birational transformations of projective spaces. We give an algorithmic analysis of…

High Energy Physics - Theory · Physics 2009-10-22 G. Falqui , C. -M. Viallet

We characterise the existentially closed models of the theory of exponential fields. They do not form an elementary class, but can be studied using positive logic. We find the amalgamation bases and characterise the types over them. We…

Logic · Mathematics 2021-01-19 Levon Haykazyan , Jonathan Kirby

In this paper, we introduce the concepts of strongly 2-absorbing primary ideals (resp., submodules) and strongly 2-absorbing ideals (resp., submodules) as generalizations of strongly prime ideals. Furthermore, we investigate some basic…

Commutative Algebra · Mathematics 2019-08-20 H. Ansari-Toroghy , F. Farshadifar , S. Maleki-Roudposhti

We introduce the concept of Almost-Companion Matrix (ACM) by relaxing the non-derogatory property of the standard Companion Matrix (CM). That is, we define an ACM as a matrix whose characteristic polynomial coincides with a given monic and…

Quantum Physics · Physics 2023-02-22 L. A. Markovich , A. Migliore , A. Messina

We extend a classification of irreducible, almost-commutative geometries whose spectral action is dynamically non-degenerate, to internal algebras that have six simple summands. We find essentially four particle models: An extension of the…

High Energy Physics - Theory · Physics 2014-11-18 Jan-Hendrik Jureit , Christoph A. Stephan

In this short note, we shall prove some observations regarding the connection between indestructible $\omega_1$-guessing models and the $\omega_1$-approximation property of forcing notions.

Logic · Mathematics 2022-02-18 Rahman Mohammadpour

In this paper, we introduce the notions of tight closure of ideals on Witt rings and quasi-tightly closedness of system of parameters. By using the notions, we obtain a characterization of quasi-$F$-rationality. Furthermore, we study the…

Algebraic Geometry · Mathematics 2024-09-11 Shou Yoshikawa

We introduce propositional team-based logics expressively complete for (quasi) downward and (quasi) upward closed properties in a syntactically dual way, by using variants of the inclusion atom. In particular, the variants of the primitive…

Logic · Mathematics 2026-03-06 Matilda Häggblom

The relation between representations and positive definite functions is a key concept in harmonic analysis on topological groups. Recently this relation has been studied on topological groupoids. This is the second in a series of papers in…

Operator Algebras · Mathematics 2016-09-07 Massoud Amini , Alireza Medghalchi