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Related papers: Variations of star selection principles on small s…

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We explore whether global observed properties, specifically half-light radii, mean surface brightness, and integrated stellar kinematics, suffice to unambiguously differentiate galaxies from star clusters, which presumably formed…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Dennis Zaritsky , Ann I. Zabludoff , Anthony H. Gonzalez

Contents of the issue: Selection Principles and special sets of reals: Open problems Winning the pressing down game but not Banach Mazur Ramsey classes of topological and metric spaces More on partitioning triples of countable ordinals…

General Topology · Mathematics 2008-12-31 Boaz Tsaban

A static, spherically symmetric spacetime with negative pressures is conjectured inside a star. The gravitational field is repulsive and so a central singularity is avoided. The positive energy density and the pressures of the imperfect…

General Relativity and Quantum Cosmology · Physics 2020-05-05 Hristu Culetu

We introduce the class $\Sigma_k(d)$ of $k$-stellated (combinatorial) spheres of dimension $d$ ($0 \leq k \leq d + 1$) and compare and contrast it with the class ${\cal S}_k(d)$ ($0 \leq k \leq d$) of $k$-stacked homology $d$-spheres. We…

Geometric Topology · Mathematics 2013-05-17 Bhaskar Bagchi , Basudeb Datta

We prove that assuming $\mathfrak{b}=\mathfrak{d}$, in the class of hereditarily Lindel\"of spaces, each productively Scheepers space is productively Hurewicz. The above statement remains true in the class of all general topological spaces…

General Topology · Mathematics 2026-02-19 Marta Kładź-Duda , Piotr Szewczak , Lyubomyr Zdomskyy

Whereas the Gerlits-Nagy gamma-property is strictly weaker than the Galvin-Miller strong gamma-property, the corresponding strong notions for the Menger, Hurewicz, Rothberger, Gerlits-Nagy (*), Arkhangel'skii and Sakai properties are…

Logic · Mathematics 2010-08-02 Boaz Tsaban

It is known that both the Menger and Hurewicz property of a Tychonoff space $X$ can be described by the way $X$ is placed in its \v{C}ech-Stone compactification $\beta X$. We provide analogous characterizations for the projective versions…

General Topology · Mathematics 2024-05-08 Mikołaj Krupski , Kacper Kucharski

Let a vector-valued sublinear operator satisfy the size condition and be bounded on weighted Lebesgue spaces with variable exponent. Then we obtain its boundedness on weighted grand Herz-Morrey spaces with variable exponents. Next we…

Functional Analysis · Mathematics 2025-02-21 Shengrong Wang , Pengfei Guo , Jingshi Xu

We study some properties of pointwise $k$-slant submanifolds of almost Hermitian manifolds with a special view towards K\"{a}hler manifolds. In particular, we characterize the integrability of the component distributions, treating also the…

Differential Geometry · Mathematics 2025-08-04 Adara M. Blaga , Dan Radu Latcu

If B is a compact space and B\{pt} is Lindelof then B^k\{pt} is star-Linedlof for every cardinality k. If B\{pt} is compact then B^k\{pt} is discretely star-Lindelof. In particular, this gives new examples of Tychonoff discretely…

General Topology · Mathematics 2007-05-23 Gady Kozma

In this paper we present a method to obtain Banach spaces of universal and almost-universal disposition with respect to a given class $\mathfrak M$ of normed spaces. The method produces, among other, the Gurari\u{\i} space $\mathcal G$ (the…

Functional Analysis · Mathematics 2011-06-28 Antonio Aviles , Felix Cabello , Jesus M. F. Castillo , Manuel Gonzalez , Yolanda Moreno

We show that filtered K-theory is equivalent to a substantially smaller invariant for all real-rank-zero C*-algebras with certain primitive ideal spaces -- including the infinitely many so-called accordion spaces for which filtered K-theory…

Operator Algebras · Mathematics 2013-11-05 Sara Arklint , Rasmus Bentmann , Takeshi Katsura

We use observed radial profiles of mass surface densities of total, $\Sigma_g$, & molecular, $\Sigma_{\rm H2}$, gas, rotation velocity & star formation rate (SFR) surface density, $\Sigma_{\rm sfr}$, of the molecular-rich ($\Sigma_{\rm…

Astrophysics of Galaxies · Physics 2015-06-19 Chutipong Suwannajak , Jonathan C. Tan , Adam K. Leroy

We study selection principles related to bornological covers using the notion of ideals. We consider ideals $\mathcal I$ and $\mathcal J$ on $\omega$ and standard ideal orderings $KB, K$. Relations between cardinality of a base of a…

General Topology · Mathematics 2024-03-08 D. Chandra , P. Das , S. Das

We study q-stars in Brans-Dicke gravitational theory. We find that when the Brans-Dicke constant, $\omega_{\textrm{BD}}$, tends to infinity, the results of General Relativity are reproduced. For other values of $\omega_{\textrm{BD}}$, the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Athanasios Prikas

The purpose of this short note is to establish an explicit equivalence between two star products $\star$ and $\star_{\log}$ on the symmetric algebra $\mathrm S(\mathfrak g)$ of a finite-dimensional Lie algebra $\mathfrak g$ over a field…

Quantum Algebra · Mathematics 2012-06-12 Carlo A. Rossi

Characterizations of paracompact finite $C$-spaces via continuous selections are given. We apply these results to obtain some properties of finite $C$-spaces. Factorization theorems and a completion theorem for finite $C$- spaces are also…

General Topology · Mathematics 2016-09-07 Vesko Valov

This paper addresses several questions of Feng, Gruenhage, and Shen which arose from Michael's theory of continuous selections from countable spaces. We construct an example of a space which is $L$-selective but not $\mathbb{Q}$-selective…

General Topology · Mathematics 2019-10-24 William Chen-Mertens , Paul J. Szeptycki

We present data for a sample of 45 spiral galaxies over a range of Hubble types, imaged in the near-IR J and K bands. Parameters are calculated describing the bulge, disk and bar K-band light distributions, and we look for correlations…

Astrophysics · Physics 2007-05-23 M. S. Seigar , P. A. James

The local space density of galaxies as a function of their basic structural parameters -luminosity, surface brightness and scale size- is still poorly known. Our poor knowledge is the result of strong selection biases against low surface…

Astrophysics · Physics 2009-10-31 Roelof S. de Jong , Cedric Lacey