Results 71 to 80 of about 1,820 (180)

LOGICS FROM ULTRAFILTERS

The Review of Symbolic Logic, 2023
AbstractUltrafilters play a significant role in model theory to characterize logics having various compactness and interpolation properties. They also provide a general method to construct extensions of first-order logic having these properties. A main result of this paper is that every class $\Omega $ of uniform ultrafilters generates a $\Delta ...
openaire   +1 more source

On strict and simple type extensions

International Journal of Mathematics and Mathematical Sciences, 1998
Let (Y,τ) be an extension of a space (X,τ′)⋅p∈Y, let 𝒪yp={W∩X:W∈τ,p∈W}. For U∈τ′, let o(U)={P∈Y:U∈𝒪yp}. In 1964, Banaschweski introduced the strict extension Y#, and the simple extension Y+ of X (induced by (Y,τ)) having base {o(U):U∈τ′} and {U∪{p}:p∈Y ...
Mohan Tikoo
doaj   +1 more source

A Choquet theory of Lipschitz‐free spaces

Proceedings of the London Mathematical Society, Volume 132, Issue 2, February 2026.
Abstract Let (M,d)$(M,d)$ be a complete metric space and let F(M)$\mathcal {F}({M})$ denote the Lipschitz‐free space over M$M$. We develop a ‘Choquet theory of Lipschitz‐free spaces’ that draws from the classical Choquet theory and the De Leeuw representation of elements of F(M)$\mathcal {F}({M})$ (and its bi‐dual) by positive Radon measures on βM ...
Richard J. Smith
wiley   +1 more source

Variation in Human Bone Collagen Turnover Among Skeletal Elements

American Journal of Biological Anthropology, Volume 189, Issue 1, January 2026.
ABSTRACT Objective Understanding tissue turnover rate is crucial for isotopic analysis. The stable isotope composition of collagen is often studied in archeology and paleontology, yet bone collagen turnover rates across various skeletal elements remain underexplored.
Olivia Hall, Shari L. Forbes, Paul Szpak
wiley   +1 more source

ON PRODUCTS OF ULTRAFILTERS

The Journal of Symbolic Logic
Abstract Assuming the Generalized Continuum hypothesis, this paper answers the question: when is the tensor product of two ultrafilters equal to their Cartesian product? It is necessary and sufficient that their Cartesian product is an ultrafilter; that the two ultrafilters commute in the tensor product; that for all cardinals ...
openaire   +2 more sources

Minimally Destructive Radiocarbon Dating of Bone

Rapid Communications in Mass Spectrometry, Volume 40, Issue 9, 15 May 2026.
ABSTRACT Rationale Bone is commonly used in radiocarbon dating in archaeology and other disciplines. Despite advances in collagen extraction protocols, the process remains destructive, requiring sawing, drilling or crushing of bone material. While non‐destructive approaches have recently been applied in ancient genomics and palaeoproteomics, no ...
Tom Higham, Katharina Luftensteiner, Laura van der Sluis, Maddalena Giannì, Maria Wiegele, Anastasia Papadogianni, Peter Steier, Daniela Gruber, Brigitte Schmidt, Katy Schmidt, Andrei Belinski, Romain Mensan, Maxim Kozlikin, Michael Shunkov, Petr Neruda, Zdeňka Nerudová, Barbara Horejs, John Schulze, Katerina Douka, Thomas W. Stafford Jr.   +19 more
wiley   +1 more source

Elementary equivalence and disintegration of tracial von Neumann algebras

Forum of Mathematics, Sigma
We prove an analog of the disintegration theorem for tracial von Neumann algebras in the setting of elementary equivalence rather than isomorphism, showing that elementary equivalence of two direct integrals of tracial factors implies fiberwise ...
David Gao, David Jekel
doaj   +1 more source

ATTRACTION SETS IN ATTAINABILITY PROBLEMS WITH ASYMPTOTIC-TYPE CONSTRAINTS

Ural Mathematical Journal
In control theory, the problem of constructing and investigating attainability domains is very important. However, under perturbations of constraints, this problem lacks stability. It is useful to single out the case when the constraints are relaxed.
Alexander G. Chentsov
doaj   +1 more source

Direct products of cyclic semigroups and left zero semigroups in $\beta\mathbb{N}$ [PDF]

Categories and General Algebraic Structures with Applications
We show that for every $n\in\mathbb{N}$, the direct product of the cyclic semigroup of order $n$ and period $1$ and the left zero semigroup $2^\mathfrak{c}$ has copies in $\beta\mathbb{N}$.
Yuliya Zelenyuk
doaj   +1 more source

c-ideals in complemented posets [PDF]

Mathematica Bohemica
In their recent paper on posets with a pseudocomplementation denoted by $*$ the first and the third author introduced the concept of a $*$-ideal. This concept is in fact an extension of a similar concept introduced in distributive pseudocomplemented ...
Ivan Chajda, Miroslav Kolařík, Helmut Länger   +2 more
doaj   +1 more source