Results 11 to 20 of about 40 (38)
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
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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
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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
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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
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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
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Note on Order‐Isomorphic Isometric Embeddings of Some Recent Function Spaces
Journal of Function Spaces, Volume 2015, Issue 1, 2015., 2015 We investigate certain recently introduced ODE‐determined varying exponent Lp spaces. It turns out that these spaces are finitely representable in a concrete universal varying exponent lp space. Moreover, this can be accomplished in a natural unified fashion.
Jarno Talponen, Hugo Leiva
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Discrimination in a General Algebraic Setting
The Scientific World Journal, Volume 2015, Issue 1, 2015., 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.
Benjamin Fine +4 more
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Approximate Preservers on Banach Algebras and C*‐Algebras
Abstract and Applied Analysis, Volume 2013, Issue 1, 2013., 2013 The aim of the present paper is to give approximate versions of Hua’s theorem and other related results for Banach algebras and C*‐algebras. We also study linear maps approximately preserving the conorm between unital C*‐algebras.
M. Burgos +3 more
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A note on properties that imply the fixed point property
Abstract and Applied Analysis, Volume 2006, Issue 1, 2006., 2006 We give relationships between some Banach‐space geometric properties that guarantee the weak fixed point property. The results extend some known results of Dalby and Xu.
S. Dhompongsa, A. Kaewkhao
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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
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