Topological classification of closed convex sets in Fréchet spaces

Taras Banakh; Robert Cauty

Studia Mathematica (2011)

  • Volume: 205, Issue: 1, page 1-11
  • ISSN: 0039-3223

Abstract

top
We prove that each non-separable completely metrizable convex subset of a Fréchet space is homeomorphic to a Hilbert space. This resolves a more than 30 years old problem of infinite-dimensional topology. Combined with the topological classification of separable convex sets due to Klee, Dobrowolski and Toruńczyk, this result implies that each closed convex subset of a Fréchet space is homeomorphic to [ 0 , 1 ] × [ 0 , 1 ) m × ( κ ) for some cardinals 0 ≤ n ≤ ω, 0 ≤ m ≤ 1 and κ ≥ 0.

How to cite

top

Taras Banakh, and Robert Cauty. "Topological classification of closed convex sets in Fréchet spaces." Studia Mathematica 205.1 (2011): 1-11. <http://eudml.org/doc/285892>.

@article{TarasBanakh2011,
abstract = {We prove that each non-separable completely metrizable convex subset of a Fréchet space is homeomorphic to a Hilbert space. This resolves a more than 30 years old problem of infinite-dimensional topology. Combined with the topological classification of separable convex sets due to Klee, Dobrowolski and Toruńczyk, this result implies that each closed convex subset of a Fréchet space is homeomorphic to $[0,1]ⁿ × [0,1)^\{m\} × ℓ₂(κ)$ for some cardinals 0 ≤ n ≤ ω, 0 ≤ m ≤ 1 and κ ≥ 0.},
author = {Taras Banakh, Robert Cauty},
journal = {Studia Mathematica},
keywords = {Fréchet and Hilbert space; convex set; separable; completely metrizable},
language = {eng},
number = {1},
pages = {1-11},
title = {Topological classification of closed convex sets in Fréchet spaces},
url = {http://eudml.org/doc/285892},
volume = {205},
year = {2011},
}

TY - JOUR
AU - Taras Banakh
AU - Robert Cauty
TI - Topological classification of closed convex sets in Fréchet spaces
JO - Studia Mathematica
PY - 2011
VL - 205
IS - 1
SP - 1
EP - 11
AB - We prove that each non-separable completely metrizable convex subset of a Fréchet space is homeomorphic to a Hilbert space. This resolves a more than 30 years old problem of infinite-dimensional topology. Combined with the topological classification of separable convex sets due to Klee, Dobrowolski and Toruńczyk, this result implies that each closed convex subset of a Fréchet space is homeomorphic to $[0,1]ⁿ × [0,1)^{m} × ℓ₂(κ)$ for some cardinals 0 ≤ n ≤ ω, 0 ≤ m ≤ 1 and κ ≥ 0.
LA - eng
KW - Fréchet and Hilbert space; convex set; separable; completely metrizable
UR - http://eudml.org/doc/285892
ER -

NotesEmbed ?

top

You must be logged in to post comments.

To embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.

Only the controls for the widget will be shown in your chosen language. Notes will be shown in their authored language.

Tells the widget how many notes to show per page. You can cycle through additional notes using the next and previous controls.

    
                

Note: Best practice suggests putting the JavaScript code just before the closing </body> tag.