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1d
revised Find the norm of operator
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2d
answered Is $\ell^1$ isomorphic to $L^1[0,1]$?
Jul
2
comment Ideals of the operator algebra
As for your second question, the ideal structure of $\mathscr B(A)$ is usually a complicated issue. See p. 2 in arxiv.org/pdf/1112.4800v1.pdf Actually there are very few Banach algebras for which the ideal structure of $\mathscr B(A)$ is completely understood.
Jul
2
revised Ideals of the operator algebra
added 26 characters in body; edited tags
Jul
2
revised Banach space and Hamel Basis cardinality
added 16 characters in body
Jul
2
revised How to show that the space of polynomials is not complete
added 56 characters in body; edited title
Jul
2
comment why separable normal space has only continuum many different open subsets?
Right, $X=\beta \mathbb{N}$ can serve as another counterexample as it is separable by the very definition.
Jul
2
reviewed Approve Product of logartithms equation.
Jun
29
answered Functional Analysis (Topological and Isometric Isomorphisms)
Jun
23
awarded  Enlightened
Jun
23
awarded  Nice Answer
Jun
17
comment Is the von neumann algebra of locally compact amenable group hyperfinite?
That's surprising (probably he had made a mistake) because if you take a separable but non-second-countable group like $\{0,1\}^{[0,1]}$ then there is a problem with the definition of hyperfiniteness (the usual conditions that we use for separably acting von Neumann algebras are no longer equivalent).
Jun
16
comment Is the von neumann algebra of locally compact amenable group hyperfinite?
Are you sure that Connes was dealing with separable (rather than second-countable) groups?
Jun
16
comment von Neumann algebra associated to the full group C*-algebra
I think I don't get it. There are still type III factors lurking behind amenable groups. The point is that they contribute nothing to the norm(s) on the algebraic group algebra.
Jun
16
comment von Neumann algebra associated to the full group C*-algebra
Thanks Martin. What worries me a little is that you make no reference to amenability whatsoever. In this case of course, the reduced and full C*-algebras are the same, yet by Glimm's result there are still representations which generate type III factors.
Jun
8
awarded  Curious
Jun
7
comment Example of a second countable space but not locally compact?
Take a separable infinite-dimensional Banach space.
Jun
7
reviewed Approve find a change of basis matrix
Jun
7
reviewed Approve Prove that $\lim_{\substack{b\to\infty \\ a\to0+}}\int_a^b\frac{\hat{f}(\xi)}\xi d\xi=-\pi i\int_0^\infty f(x)dx$
Jun
7
asked von Neumann algebra associated to the full group C*-algebra