Results 11 to 20 of about 111 (106)

Discrimination in a General Algebraic Setting. [PDF]

ScientificWorldJournal, 2015
Discriminating groups were introduced by G. Baumslag, A. Myasnikov, and V. Remeslennikov as an outgrowth of their theory of algebraic geometry over groups. Algebraic geometry over groups became the main method of attack on the solution of the celebrated Tarski conjectures.
Fine B, Gaglione A, Lipschutz S, Spellman D.   +3 more
europepmc   +2 more sources

Approximate isomorphism of metric structures

Mathematical Logic Quarterly, Volume 69, Issue 4, Page 482-507, November 2023., 2023
Abstract We give a formalism for approximate isomorphism in continuous logic simultaneously generalizing those of two papers by Ben Yaacov [2] and by Ben Yaacov, Doucha, Nies, and Tsankov [6], which are largely incompatible. With this we explicitly exhibit Scott sentences for the perturbation systems of the former paper, such as the Banach‐Mazur ...
James E. Hanson
wiley   +1 more source

The indecomposable objects in the center of Deligne's category Re̲pSt$\protect\underline{{\rm Re}}\!\operatorname{p}S_t$

Proceedings of the London Mathematical Society, Volume 126, Issue 4, Page 1134-1181, April 2023., 2023
Abstract We classify the indecomposable objects in the monoidal center of Deligne's interpolation category Re̲pSt$\underline{{\rm Re}}\!\operatorname{p}S_t$ by viewing Re̲pSt$\underline{{\rm Re}}\!\operatorname{p}S_t$ as a model‐theoretic limit in rank and characteristic.
Johannes Flake, Nate Harman, Robert Laugwitz   +2 more
wiley   +1 more source

Finite axiomatizability for profinite groups

Proceedings of the London Mathematical Society, Volume 123, Issue 6, Page 597-635, December 2021., 2021
Abstract A group is finitely axiomatizable (FA) in a class C if it can be determined up to isomorphism within C by a sentence in the first‐order language of group theory. We show that profinite groups of various kinds are FA in the class of profinite groups, or in the class of pro‐p groups for some prime p.
Andre Nies, Dan Segal, Katrin Tent
wiley   +1 more source

An Overview of Saharon Shelah's Contributions to Mathematical Logic, in Particular to Model Theory

Theoria, Volume 87, Issue 2, Page 349-360, April 2021., 2021
Abstract I will give a brief overview of Saharon Shelah's work in mathematical logic. I will focus on three transformative contributions Shelah has made: stability theory, proper forcing and PCF theory. The first is in model theory and the other two are in set theory.
Jouko Väänänen
wiley   +1 more source

On the decoupled Markov group conjecture

Bulletin of the London Mathematical Society, Volume 53, Issue 1, Page 240-247, February 2021., 2021
Abstract The Markov group conjecture, a long‐standing open problem in the theory of Markov processes with countable state space, asserts that a strongly continuous Markov semigroup T=(Tt)t∈[0,∞) on ℓ1 has bounded generator if the operator T1 is bijective. Attempts to disprove the conjecture have often aimed at glueing together finite‐dimensional matrix
Jochen Glück
wiley   +1 more source

Integral Superposition‐Type Operators on Some Analytic Function Spaces

Journal of Function Spaces, Volume 2021, Issue 1, 2021., 2021
All entire functions which transform a class of holomorphic Zygmund‐type spaces into weighted analytic Bloch space using the so‐called n‐generalized superposition operator are characterized in this paper. Moreover, certain specific properties such as boundedness and compactness of the newly defined class of generalized integral superposition operators ...
A. El-Sayed Ahmed, S. Omran, Gen Qi Xu
wiley   +1 more source

Further Properties of 1‐ and 2‐Dimensional U‐ and W‐Convexity and Fixed Point of Nonexpansive Mappings in Banach Spaces X and X∗

Journal of Mathematics, Volume 2021, Issue 1, 2021., 2021
In this paper, we further studied properties of the modulus of n‐dimensional U‐convexity and the modulus of n‐dimensional U‐flatness when n = 1 (2‐dimensional character) and n = 2 (3‐dimensional character). The new properties of these moduli are investigated, and the relationships between these moduli and other geometric parameters of Banach spaces are
Ji Gao, Zoran Mitrovic
wiley   +1 more source

Nonstandard characterisations of tensor products and monads in the theory of ultrafilters

Mathematical Logic Quarterly, Volume 65, Issue 3, Page 347-369, October 2019., 2019
Abstract We use nonstandard methods, based on iterated hyperextensions, to develop applications to Ramsey theory of the theory of monads of ultrafilters. This is performed by studying in detail arbitrary tensor products of ultrafilters, as well as by characterising their combinatorial properties by means of their monads.
Lorenzo Luperi Baglini
wiley   +1 more source

Generalized free wreath products and their operator algebras

Journal of the London Mathematical Society, Volume 113, Issue 6, June 2026.
Abstract We develop a new approach on free wreath products, generalizing the constructions of Bichon and of Fima‐Pittau. We show stability properties for certain approximation properties such as exactness, Haagerup property, hyperlinearity, and K‐amenability. We study qualitative properties of the associated von Neumann algebra: factoriality, primeness,
Pierre Fima, Arthur Troupel
wiley   +1 more source