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Related papers: Generic stability, regularity, and quasiminimality

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We begin a systematic development of structure theory for a first order theory, which is stable over a monadic predicate. We show that stability over a predicate implies quantifier free definability of types over stable sets, introduce an…

Logic · Mathematics 2023-02-17 Saharon Shelah , Alexander Usvyatsov

We investigate the automorphism groups of $\aleph\_0$-categorical structures and prove that they are exactly the Roelcke precompact Polish groups. We show that the theory of a structure is stable if and only if every Roelcke uniformly…

Logic · Mathematics 2015-12-23 Itaï Ben Yaacov , Todor Tsankov

We study two notions of concentration for homogeneous polynomials of degree $N$ in $d+1$ complex variables on the unit sphere: a local notion measuring the fraction of the $L^2$-norm supported on a measurable subset; and a global notion…

Classical Analysis and ODEs · Mathematics 2026-03-17 María Ángeles García-Ferrero , Joaquim Ortega-Cerdà

We discuss homogeneity and universality issues in the theory of abstract linear spaces, namely, structures with points and lines satisfying natural axioms, as in Euclidean or projective geometry. We show that the two smallest projective…

Logic · Mathematics 2022-05-27 Wiesław Kubiś , Piotr Nowakowski , Tomasz Rzepecki

A discrete countable group G is matricially stable if the finite dimensional approximate unitary representations of G are perturbable to genuine representations in the point-norm topology. For large classes of groups G, we show that…

Operator Algebras · Mathematics 2021-03-19 Marius Dadarlat

We examine properties of generic automorphisms of the random poset, with the goal of explicitly characterizing them. We associate to each automorphism an auxiliary first-order structure, consisting of the random poset equipped with an…

Logic · Mathematics 2021-01-01 Dakota Thor Ihli

Given a cover $\mathbb{U}$ of a family of smooth complex algebraic varieties, we associate with it a class $\mathcal{U},$ containing $\mathbb{U}$, of structures locally definable in an o-minimal expansion of the reals. We prove that the…

Logic · Mathematics 2024-05-01 Boris Zilber

Regular groups and fields are common generalizations of minimal and quasi-minimal groups and fields, so the conjectures that minimal or quasi-minimal fields are algebraically closed have their common generalization to the conjecture that…

Logic · Mathematics 2012-11-19 Tomasz Gogacz , Krzysztof Krupinski

For every algebraically closed field $\boldsymbol k$ of characteristic different from $2$, we prove the following: (1) Generic finite dimensional (not necessarily associative) $\boldsymbol k$-algebras of a fixed dimension, considered up to…

Algebraic Geometry · Mathematics 2015-01-20 Vladimir L. Popov

Quasiminimal structures play an important role in non-elementary categoricity. In this paper we explore possibilities of constructing quasiminimal models of a given first-order theory. We present several constructions with increasing…

Logic · Mathematics 2015-10-21 Levon Haykazyan

We explore a notion of pseudofinite dimension, introduced by Hrushovski and Wagner, on an infinite ultraproduct of finite structures. Certain conditions on pseudofinite dimension are identified that guarantee simplicity or supersimplicity…

Logic · Mathematics 2014-10-01 Dario Garcia , Dugald Macpherson , Charles Steinhorn

We prove a new kind of homological stability theorem for automorphism groups of finitely-generated projective modules over Dedekind domains, which takes into account all possible stabilisation maps between these, rather than only…

Commutative Algebra · Mathematics 2024-05-14 Oscar Randal-Williams

In this article we prove the topological minimality of unions of several almost orthogonal planes of arbitrary dimensions. A particular case was proved in arXiv:1103.1468, where we proved the Almgren minimality (which is a weaker property…

Classical Analysis and ODEs · Mathematics 2013-12-13 Xiangyu Liang

We study stable like behaviour in first order theories without the independence property. We introduce generically stable measures, give characterizatiions, and show their ubiquity. We also introduce generic compact domination. We also…

Logic · Mathematics 2010-02-26 Ehud Hrushovski , Anand Pillay , Pierre Simon

In this paper we study the linear stability of the relative equilibria for homogeneous and quasihomogeneous potentials. Firstly, in the case the potential is a homogeneous function of degree $-a$, we find that any relative equilibrium of…

Mathematical Physics · Physics 2009-09-29 Manuele Santoprete

We study analytic Zariski structures from the point of view of non-elementary model theory. We show how to associate an abstract elementary class with a one-dimensional analytic Zariski structure and prove that the class is stable,…

Logic · Mathematics 2016-01-13 Boris Zilber

We consider existence and stability of an almost periodic solution of the quasilinear system of differential equations with piecewise constant argument of generalized type. The associated linear homogeneous system satisfies exponential…

Dynamical Systems · Mathematics 2016-09-07 M. U. Akhmet

We propose a unifying general (i.e. not assuming the mapping to have any particular structure) view on the theory of regularity and clarify the relationships between the existing primal and dual quantitative sufficient and necessary…

Optimization and Control · Mathematics 2023-06-22 Nguyen Duy Cuong , Alexander Y. Kruger

In this paper, we pose the concepts of pre-topological groups and some generalizations of pre-topological groups. First, we systematically investigate some basic properties of pre-topological groups; in particular, we prove that each…

General Topology · Mathematics 2022-03-22 Fucai Lin , Ting Wu , Yufan Xie , Meng Bao

It is, by now, classical that lattices in higher rank semisimple groups have various rigidity properties. In this work, we add another such rigidity property to the list: uniform stability with respect to the family of unitary operators on…

Group Theory · Mathematics 2023-07-11 Lev Glebsky , Alexander Lubotzky , Nicolas Monod , Bharatram Rangarajan