Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 20746

Banach spaces, function spaces, real functions, integral transforms, theory of distributions, measure theory.

5 votes
2 answers
1k views

Polar decomposition in C*-algebras

A very nice feature of W*-algebras is the following: once you have an element $a$ of a W*-algebra $M$, and $a=u|a|$ (the polar decomposition), then $u\in M$. It seems that it carries over to AW*-alg …
Jan Veselý's user avatar
4 votes
1 answer
357 views

Density character of $\ell_\infty(\kappa, S)$

Let $S$ be an uncountable set. Consider the subspace $\ell_\infty(\kappa, S)$ of $\ell_\infty(S)$ formed by all functions with support of cardinality at most $\kappa$ (here $\kappa<|S|$). Certainly, $ …
Jan Veselý's user avatar
3 votes
1 answer
498 views

When an AW*-algebra is a W*-algebra

In a very old book of Kaplansky "Rings of operators", on p. 123 one can find the following sentence: It is a standing conjecture that an AW${}^\ast$-algebra is W${}^\ast$ if its center is W${}^\ast$. …
Jan Veselý's user avatar
-1 votes
2 answers
406 views

Almost isometric subspaces of $\ell_p$

1) Given $p\in (1,\infty)$. 2) Let us fix two, non-isometric subspaces $X,Y\subseteq \ell_p$ isomorphic to $\ell_p$. 3) Are there an $\varepsilon\in (0,1)$ and an isomorphism $S\colon X\to Y$ such …
Jan Veselý's user avatar