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Related papers: Musing on Kunen's compact $L$-space

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We prove that if $K$ and $L$ are compact spaces and $C(K)$ and $C(L)$ are isomorphic as Banach spaces then $K$ has a $\pi$-base consisting of open sets $U$ such that $\bar{U}$ is a continuous image of some compact subspace of $L$. This…

Functional Analysis · Mathematics 2013-09-20 Grzegorz Plebanek

We prove that there is a compact space $L$ and a 1-complemented subspace of the Banach space $C(L)$ which is not isomorphic to a space of continuous functions.

Functional Analysis · Mathematics 2023-05-09 Grzegorz Plebanek , Alberto Salguero Alarcón

We construct a totally disconnected compact Hausdorff space N which has clopen subsets M included in L included in N such that N is homeomorphic to M and hence C(N) is isometric as a Banach space to C(M) but C(N) is not isomorphic to C(L).…

Functional Analysis · Mathematics 2011-06-16 Piotr Koszmider

We prove that if continuum is not a Kunen cardinal, then there is a uniform Eberlein compact space $K$ such that the Banach space $C(K)$ does not embed isometrically into $\ell_\infty/c_0$. We prove a similar result for isomorphic…

Functional Analysis · Mathematics 2018-12-12 Mikolaj Krupski , Witold Marciszewski

Assuming $\mathfrak p=\mathfrak c$, we show that for every Eberlein compact space $L$ of weight $\mathfrak c$ there exists a short exact sequence $0\to c_0\to X\to C(L)\to 0$, where the Banach space $X$ is not isomorphic to a $C(K)$-space.

Functional Analysis · Mathematics 2026-02-20 Grzegorz Plebanek , Alberto Salguero-Alarcón

We investigate the following general problem, closely related to the problem of isomorphic classification of Banach spaces $C(K)$ of continuous real-valued functions on a compact space $K$, equipped with the supremum norm: Let $\mathcal{K}$…

Functional Analysis · Mathematics 2026-03-17 Maciej Korpalski , Piotr Koszmider , Witold Marciszewski

A classical result of Cembranos and Freniche states that the C(K, X) spaces contains a complemented copy of c_0 whenever K is an infinite compact Hausdorff space and X is an infinite dimensional Banach space. This paper takes this result as…

Functional Analysis · Mathematics 2015-03-17 Dale E. Alspach , Elói Medina Galego

It is proved that for every compact metric space $K$ there exists a Banach space $X$ whose Calkin algebra $\mathcal{L}(X)/\mathcal{K}(X)$ is homomorphically isometric to $C(K)$. This is achieved by appropriately modifying the…

Functional Analysis · Mathematics 2023-03-08 Pavlos Motakis

We prove that for any separable Banach space $X$, there exists a compact metric space which is homeomorphic to the Cantor space and whose Lipschitz-free space contains a complemented subspace isomorphic to $X$. As a consequence we give an…

Functional Analysis · Mathematics 2015-11-17 Petr Hájek , Gilles Lancien , Eva Pernecká

The isometric universality of the spaces $C(K)$ for $K$ a non scattered Hausdorff compact does not take into account the ``quality'' of the representation. Indeed, the existence of an isometric copy of a separable Banach space $X$ into…

Functional Analysis · Mathematics 2024-06-25 Matias Raja

We study the classification of spaces of continuous functions $C(K)$ under positive linear maps. For infinite countable compacta, we show that whenever $C(K)$ and $C(L)$ are isomorphic, there exists an isomorphism $T:C(K)\to C(L)$…

Functional Analysis · Mathematics 2026-01-19 Marek Cúth , Jonáš Havelka , Jakub Rondoš , Bünyamin Sarı

We introduce the notion that a zero-dimensional compact space $L$ is a \emph{Boolean image} of an arbitrary compact space $K$. When $K$ is also zero-dimensional, this just means that $L$ is a continuous image of $K$. However, a number of…

General Topology · Mathematics 2019-08-20 Antonio Avilés , Grzegorz Plebanek

The main result of this paper is that the space of conformally compact Einstein metrics on a given manifold is a smooth, infinite dimensional Banach manifold, provided it is non-empty, generalizing earlier work of Graham-Lee and Biquard. We…

Differential Geometry · Mathematics 2010-03-16 Michael T. Anderson

Supplementing and expanding classical results, for compact spaces $K$ and $L$, $L$ metric, and their Banach spaces $\mathcal{C}(L)$ and $\mathcal{C}(K)$ of continuous real-valued functions, we provide several characterizations of the…

Functional Analysis · Mathematics 2024-11-28 Jakub Rondoš , Damian Sobota

We show that there exist infinite-dimensional extremely non-complex Banach spaces, i.e. spaces $X$ such that the norm equality $\|Id + T^2\|=1 + \|T^2\|$ holds for every bounded linear operator $T:X\longrightarrow X$. This answers in the…

Functional Analysis · Mathematics 2008-11-26 Piotr Koszmider , Miguel Martin , Javier Meri

We construct a ZFC example of a nonmetrizable compact space $K$ such that every totally disconnected closed subspace $L\subseteq K$ is metrizable. In fact, the construction can be arranged so that every nonmetrizable compact subspace may be…

General Topology · Mathematics 2015-09-18 Piotr Koszmider

We study Banach spaces $C(K)$ of real-valued continuous functions from the finite product of compact lines. It turns out that the topological character of these compact lines can be used to distinguish whether two spaces of continuous…

Functional Analysis · Mathematics 2025-07-23 Maciej Korpalski

In this note we study the structure of Lipschitz-free Banach spaces. We show that every Lipschitz-free Banach space over an infinite metric space contains a complemented copy of $\ell_1$. This result has many consequences for the structure…

Functional Analysis · Mathematics 2018-02-09 Marek Cuth , Michal Doucha , Przemyslaw Wojtaszczyk

We present a necessary condition for a pair of $\mathcal{C}(K)$ spaces to be isomorphic in terms of topological properties of Cantor-Bendixon derivatives of $K$. This in particular gives a completely new information about the perfect…

Functional Analysis · Mathematics 2023-05-12 Jakub Rondoš

We show the existence of a compact metric space $K$ such that whenever $K$ embeds isometrically into a Banach space $Y$, then any separable Banach space is linearly isometric to a subspace of $Y$. We also address the following related…

Functional Analysis · Mathematics 2008-01-17 Yves Dutrieux , Gilles Lancien
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