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We use weighted polynomial approximation to prove the existence of a compact set K with non-empty interior and a function f is dense in the space A(K) of all continuous functions on K that are holomorphic in the interior of K, endowed with…

复变函数 · 数学 2025-06-26 Stéphane Charpentier , Konstantinos Maronikolakis

In this note, we prove that if a compact even dimensional manifold $M^{n}$ with negative sectional curvature is homotopic to some compact space-like manifold $N^{n}$, then the Euler characteristic number of $M^{n}$ satisfies…

微分几何 · 数学 2015-11-17 Bing-Long Chen , Kun Zhang

Let $M = G/H$ be a connected simply connected homogeneous manifold of a compact, not necessarily connected Lie group $G$. We will assume that the isotropy $H$-module $\mathfrak {g/h}$ has a simple spectrum, i.e. irreducible submodules are…

微分几何 · 数学 2013-05-17 Michail M. Graev

In this paper we develop an analogue of the Berkovich analytification for non-necessarily algebraic complex spaces. We apply this theory to generalize to arbitrary compact K\"ahler manifolds a result of Chi Li, proving that a stronger…

微分几何 · 数学 2025-09-22 Pietro Mesquita-Piccione

We introduce the space of infinite volume ends of a locally compact second countable (lcsc) space that admits a Radon measure. In certain cases, this coincides with the classical space of ends. Consider a discrete subgroup $\Gamma$ of a…

群论 · 数学 2025-09-30 Konrad Wróbel

All spaces are assumed to be separable and metrizable. Ostrovsky showed that every zero-dimensional Borel space is $\sigma$-homogeneous. Inspired by this theorem, we obtain the following results: assuming $\mathsf{AD}$, every…

一般拓扑 · 数学 2023-07-18 Andrea Medini , Zoltán Vidnyánszky

We present simple examples of finite-dimensional connected homogeneous spaces (they are actually topological manifolds) with nonhomogeneous and nonrigid factors. In particular, we give an elementary solution of an old problem in general…

几何拓扑 · 数学 2012-03-21 M. Cárdenas , F. F. Lasheras , A. Quintero , D. Repovš

We determine the homeomorphism type of the space of smooth complete nonnegatively curved metrics on surfaces of positive Euler characteristic equipped with the topology of $C^\gamma$ uniform convergence on compact sets, when $\gamma$ is…

微分几何 · 数学 2017-03-03 Taras Banakh , Igor Belegradek

We prove that the surface gravity of a compact non-degenerate Cauchy horizon in a smooth vacuum spacetime, can be normalized to a non-zero constant. This result, combined with a recent result by Oliver Petersen and Istv\'an R\'acz, end up…

广义相对论与量子宇宙学 · 物理学 2020-06-17 Martín Reiris , Ignacio Bustamante

In this paper we prove that a complete noncompact manifold with nonnegative Ricci curvature has a trivial codimension one homology unless it is a split or flat normal bundle over a compact totally geodesic submanifold. In particular, we…

微分几何 · 数学 2007-05-23 Zhongmin Shen , Christina Sormani

We continue our study of heterotic compactifications on non-Kahler complex manifolds with torsion. We give further evidence of the consistency of the six-dimensional manifold presented earlier and discuss the anomaly cancellation and…

高能物理 - 理论 · 物理学 2010-04-06 Katrin Becker , Melanie Becker , Keshav Dasgupta , Paul S. Green , Eric Sharpe

It is well-known that the consistency strength of the GCH failing at a measurable cardinal is the existence of a cardinal $\kappa$ with $o(\kappa)=\kappa^{++}$. As the literature does not contain more than a proof sketch of the lower bound…

逻辑 · 数学 2025-01-03 Connor Watson

We prove that the free locally convex space $L(X)$ over a metrizable space $X$ has countable tightness if and only if $X$ is separable.

一般拓扑 · 数学 2014-07-08 S. S. Gabriyelyan

We give several topological/combinatorial conditions that, for a filter on $\omega$, are equivalent to being a non-meager $\mathsf{P}$-filter. In particular, we show that a filter is countable dense homogeneous if and only if it is a…

一般拓扑 · 数学 2014-10-07 Kenneth Kunen , Andrea Medini , Lyubomyr Zdomskyy

We prove that compact Hausdorff spaces with a $\mathbb{P}$-diagonal are metrizable.

一般拓扑 · 数学 2016-09-02 Alan Dow , Klaas Pieter Hart

The Noetherian type of a space is the least $\kappa$ such that it has a base that is $\kappa$-like with respect to containment. Just as all known homogeneous compacta have cellularity at most $2^\omega$, they satisfy similar upper bounds in…

一般拓扑 · 数学 2010-01-05 David Milovich

We argue that the Karch-Randall compactification is holographically dual to a 4-d conformal field theory coupled to gravity on Anti de Sitter space. Using this interpretation we recover the mass spectrum of the model. In particular, we find…

高能物理 - 理论 · 物理学 2009-11-07 Massimo Porrati

Let $M$ be a compact Riemannian manifold, $\pi:\widetilde{M}\rightarrow M$ be the universal covering and $\omega$ be a smooth $2$-form on $M$ with $\pi^*\omega$ cohomologous to zero. Suppose the fundamental group $\pi_1(M)$ satisfies…

微分几何 · 数学 2018-03-01 Bing-Long Chen , Xiaokui Yang

We study linearly ordered spaces which are Valdivia compact in their order topology. We find an internal characterization of these spaces and we present a counter-example disproving a conjecture posed earlier by the first author. The…

一般拓扑 · 数学 2012-10-23 Ondrej Kalenda , Wieslaw Kubis

Given a closed Riemannian manifold $(N^{n+1},g)$, $n+1 \geq 3$ we prove the compactness of the space of singular, minimal hypersurfaces in $N$ whose volumes are uniformly bounded from above and the $p$-th Jacobi eigenvalue $\lambda_p$'s are…

微分几何 · 数学 2024-06-21 Akashdeep Dey