Results 21 to 30 of about 40 (38)

Classification of injective factors: The wok of Alain Connes

International Journal of Mathematics and Mathematical Sciences, Volume 6, Issue 1, Page 1-39, 1983., 1983
The fundamental results of A. Connes which determine a complete set of isomorphism classes for most injective factors are discussed in detail. After some introductory remarks which lay the foundation for the subsequent discussion, an historical survey of some of the principal lines of the investigation in the classification of factors is presented ...
Steve Wright
wiley   +1 more source

Is every product system concrete?

Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.
Abstract Is every product system of Hilbert spaces over a semigroup P$P$ concrete, that is, isomorphic to the product system of an E0$E_0$‐semigroup over P$P$? The answer is no if P$P$ is discrete, cancellative and does not embed in a group. However, we show that the answer is yes for a reasonable class of semigroups.
S. Sundar
wiley   +1 more source

A removal lemma for ordered hypergraphs

Proceedings of the London Mathematical Society, Volume 130, Issue 1, January 2025.
Abstract We prove a removal lemma for induced ordered hypergraphs, simultaneously generalizing Alon–Ben‐Eliezer–Fischer's removal lemma for ordered graphs and the induced hypergraph removal lemma. That is, we show that if an ordered hypergraph (V,G,<)$(V,G,<)$ has few induced copies of a small ordered hypergraph (W,H,≺)$(W,H,\prec)$ then there is a ...
Henry Towsner
wiley   +1 more source

Finite Lattices Generating Not Finitely–Based and Nonstandard Quasivarieties

Journal of Mathematics, Volume 2025, Issue 1, 2025.
There are two well‐known and closely related problems in lattice theory: Which finite lattices generate finitely‐based quasivarieties? and Which finite lattices generate standard quasivarieties? The main goal of the paper is to contribute to both problems.
M. A. Arapbay, A. O. Basheyeva, S. M. Lutsak, Ljubisa Kocinac   +3 more
wiley   +1 more source

Compactness in team semantics

Mathematical Logic Quarterly, Volume 70, Issue 2, Page 142-161, May 2024.
Abstract We provide two proofs of the compactness theorem for extensions of first‐order logic based on team semantics. First, we build upon Lück's [16] ultraproduct construction for team semantics and prove a suitable version of Łoś' Theorem. Second, we show that by working with suitably saturated models, we can generalize the proof of Kontinen and ...
Joni Puljujärvi, Davide Emilio Quadrellaro   +1 more
wiley   +1 more source

Formal model theory and higher topology

Mathematical Logic Quarterly, Volume 70, Issue 1, Page 111-125, February 2024.
Abstract We study the 2‐categories BIon, of (generalized) bounded ionads, and Accω$\text{Acc}_\omega$, of accessible categories with directed colimits, as an abstract framework to approach formal model theory. We relate them to topoi and (lex) geometric sketches, which serve as categorical specifications of geometric theories. We provide reconstruction
Ivan Di Liberti
wiley   +1 more source

Ultraproducts of continuous posets

Algebra Universalis, 2016
Hajnal Andreka, István Németi
exaly  

Linear spaces with probability measures, ultraproducts and contiguity

Lobachevskii Journal of Mathematics, 2014
Samigulla Haliullin
exaly  

Automorphism Groups of Ultraproducts of Finite Symmetric Groups

Communications in Algebra, 2011
Simon Thomas, Philipp Lücke
exaly  

The depth of ultraproducts of Boolean algebras

Algebra Universalis, 2005
Saharon Shelah
exaly