Take the tour ×  Do there exist, either in the literature or in
folklore, theorems that characterize some particular $\ell^p$
space(s) ($p\not=1,2,\infty$)?  Such a theorem should reveal the
particular space(s) as somehow idiosyncratic, in the sense that
no obvious modification of the characterization works for
general $\ell^p$ spaces.  Thus it would not be interesting here
to learn, say, that $\ell^3$ alone has a dual isomorphic to
$\ell^{3/2}$; obviously this just specializes a general fact
from the theory of all the $\ell^p$'s.  share|improve this
question Are you expecting a "best" answer or are you looking
for a bunch of good answers? In the former case, I think this
question might deserve to be made "community wiki", but I am
open to persuasion. –  Captain Oates Dec 13 '10 at 7:18 Are you
expecting a "best" answer or are you looking for a bunch of good
answers? I think I'll see how the response unfolds for a day or
so, and then decide whether to opt for "community wiki." For
example, a priori I couldn't