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Related papers: Universally measurable sets may all be Delta^1_2

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We show that there are uncountably many algebraic extensions of $\mathbb{Q}$ containing at most finitely many moduli of CM simple principally polarized abelian varieties of any fixed dimension $g\geqslant1$, generalizing a result of…

Number Theory · Mathematics 2026-03-18 Shu Kawaguchi , Fabien Pazuki

In this paper, we study a class of two-dimensional Finsler metrics defined by a Riemannian metric $\alpha$ and a 1-form $\beta$. We characterize those metrics which are Douglasian or locally projectively flat by some equations. In…

Differential Geometry · Mathematics 2013-02-14 Guojun Yang

We prove that every unconditionally summable sequence in a Hilbert space can be factorized as the product of a square summable scalar sequence and a Bessel sequence. Some consequences on the representation of unconditionally convergent…

Functional Analysis · Mathematics 2016-11-15 Carmen Fernández , Antonio Galbis , Eva Primo

We study the structural regularities and irregularities of the reals in inner models of set theory. Starting with $L$, G\"{o}del's constructible universe, our study of the reals is thus two-fold. On the one hand, we study how their…

Logic · Mathematics 2022-08-16 Martín Soto Quintanilla

It is well known to generalize the meagre ideal replacing aleph_0 by a (regular) cardinal lambda > aleph_0 and requiring the ideal to be lambda^+-complete. But can we generalize the null ideal? In terms of forcing, this means finding a…

Logic · Mathematics 2017-01-20 Saharon Shelah

This paper introduces the expanded real numbers as an ordered subring of the hyperreal number field that does not contain any infinitesimals, and defines the set of all integrable functions from the real numbers to the expanded real…

General Mathematics · Mathematics 2021-10-01 Marcoen J. T. F. Cabbolet

We prove that it is consistent (relative to a Mahlo cardinal) that all projective sets of reals are Lebesgue measurable, but there is a $\Delta^1_3$ set without the Baire property. The complexity of the set which provides a counterexample…

Logic · Mathematics 2022-10-11 Sy Friedman , David Schrittesser

In generic realizability for set theories, realizers treat unbounded quantifiers generically. To this form of realizability, we add another layer of extensionality by requiring that realizers ought to act extensionally on realizers, giving…

Logic · Mathematics 2020-12-22 Emanuele Frittaion , Michael Rathjen

This short survey of recent work in tile self-assembly discusses the use of simulation to classify and separate the computational and expressive power of self-assembly models. The journey begins with the result that there is a single…

Computational Geometry · Computer Science 2013-09-06 Damien Woods

In $\mathsf{ZFC}$, if there is a measurable cardinal with infinitely many Woodin cardinals below it, then for every equivalence relation $E \in L(\mathbb{R})$ on $\mathbb{R}$ with all $\mathbf{\Delta}_1^1$ classes and every $\sigma$-ideal…

Logic · Mathematics 2016-08-18 William Chan , Menachem Magidor

Answering two questions of D. Fremlin [Real-valued measurable cardinals, in Set Theory of the Reals, H. Judah ed. 1993, 151-305 ] we show the following: (1) If c is real-valued measurable then the Maharam type of (c,P(c),sigma) is 2^c. (2)…

Logic · Mathematics 2016-09-06 Moti Gitik , Saharon Shelah

In this paper, we study necessary and sufficient conditions for the existence of categorical universal coverings using open covers of a given space $X$. As some applications, first we present a generalized version of the Shelah Theorem…

Algebraic Topology · Mathematics 2013-11-05 Ali Pakdaman , Hamid Torabi , Behrooz Mashayekhy

Fix a set-theoretic universe $V$. We look at small extensions of $V$ as generalised degrees of computability over $V$. We also formalise and investigate the complexity of certain methods one can use to define, in $V$, subclasses of degrees…

Logic · Mathematics 2025-01-03 Desmond Lau

The new concept of relative generic subsets is introduced. It is shown that the set of controllable linear finite-dimensional port-Hamiltonian systems is a relative generic subset of the set of all linear finite-dimensional port-Hamiltonian…

Dynamical Systems · Mathematics 2021-04-07 Jonas Kirchhoff

We relate duality mappings to the "Babbage equation" F(F(z)) = z, with F a map linking weak- to strong-coupling theories. Under fairly general conditions F may only be a specific conformal transformation of the fractional linear type. This…

Statistical Mechanics · Physics 2015-01-08 Zohar Nussinov , Gerardo Ortiz , Mohammad-Sadegh Vaezi

In this work we construct a infinite dimensional $\ell$-super Galilean conformal algebra, which is a generalization of the $\ell=1$ algebra found in the literature. We give a classification of central extensions, the vector field…

Mathematical Physics · Physics 2016-12-21 N. Aizawa , J. Segar

In this paper, we find a criterium for universal equivalence of partially commutative Lie algebras whose defining graphs are trees. Besides, we obtain bases for partially commutative metabelian Lie algebras.

Rings and Algebras · Mathematics 2012-07-10 Evgeny Poroshenko , Evgeny Timoshenko

Let $F$ be a finite extension of $Q_p$, $p>2$. We construct admissible unitary completions of certain representations of $GL_2(F)$ on $L$-vector spaces, where $L$ is a finite extension of $F$. When $F=Q_p$ using the results of Berger,…

Representation Theory · Mathematics 2008-05-08 Vytautas Paskunas

It is shown the construction of a module structure [2] with universe over a set of a particular kind of mathematical proofs, the base ring of this module will be built on a maximal consistent extension of a set of propositions, this…

Logic · Mathematics 2013-07-25 Kevin Davila Castellar , Ismael Gutierrez Garcia

A cohesive power of a computable structure is an effective ultrapower where a cohesive set acts as an ultrafilter. Let $\omega$, $\zeta$, and $\eta$ denote the respective order-types of the natural numbers, the integers, and the rationals.…

Logic · Mathematics 2023-10-11 Paul Shafer