Results 21 to 30 of about 109 (103)
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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Approximations of Theories of Unars
Қарағанды университетінің хабаршысы. Математика сериясыLo´s’s theorem states that a first-order formula holds in an ultraproduct of structures if and only if it holds in “almost all” factors, where “almost all” is understood in terms of a given ultrafilter.
N.D. Markhabatov
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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
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MODEL THEORY AND ULTRAPRODUCTS [PDF]
Proceedings of the International Congress of Mathematicians (ICM 2018), 2019 The article motivates recent work on saturation of ultrapowers from a general mathematical point of view.
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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
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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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Accessible operators on ultraproducts of Banach spaces
Extracta MathematicaeWe address a question by Henry Towsner about the possibility of representing linear operators between ultraproducts of Banach spaces by means of ultraproducts of nonlinear maps.
Félix Cabello Sánchez
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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 +3 more
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On P‐ and p‐Convexity of Banach Spaces
Abstract and Applied Analysis, Volume 2010, Issue 1, 2010., 2010 We show that every U‐space and every Banach space X satisfying δX(1) > 0 are P(3)‐convex, and we study the nonuniform version of P‐convexity, which we call p‐convexity.
Omar Muñiz-Pérez, Stevo Stevic
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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 +1 more
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