Skip to main content
12 events
when toggle format what by license comment
Oct 31, 2018 at 11:29 comment added Caleb Eckhardt @MarkRoelands Yes that is what I mean to say (unless you by 'atom' you mean something different than 'minimal projection'). Non-zero positive functionals won't give you a one-dimensional C*-algebra quotient unless those functionals happen to be multiplicative.
Oct 31, 2018 at 8:49 comment added Mark Roelands @ Caleb Eckhardt. Do you mean to say that $A$ has no ideals of co-dimension one if and only if $A^{**}$ has no central atoms, because non-zero functionals always give you one-dimensional quotients?
Oct 29, 2018 at 16:19 comment added Caleb Eckhardt I'm not sure what kind of condition you are looking for. But if you just translate '$A^{* *}$ has a projection that is both central and minimal' into a statement about $A$ you obtain '$A$ has a one-dimensional quotient.'
Oct 28, 2018 at 10:30 history edited David Roberts CC BY-SA 4.0
added 27 characters in body; edited title
Oct 28, 2018 at 6:50 history edited Martin Sleziak CC BY-SA 4.0
corrected a minor typo + added a Google Books link
S Oct 27, 2018 at 11:51 history suggested Ali Taghavi
I add a tag.
Oct 27, 2018 at 11:36 review Suggested edits
S Oct 27, 2018 at 11:51
Oct 27, 2018 at 9:43 comment added Mark Roelands You could ask the same question for JB-algebras: Is there a characterisation for those JB-algebras that have no central projections in the bidual?
Oct 27, 2018 at 9:37 comment added YCor OK thanks, but how is this connected to the question?
Oct 27, 2018 at 9:00 comment added Mark Roelands Because the self-adjoint part of a $C$*-algebra is a Jordan algebra (in fact it is a JB-algebra) with the product $x\circ y:=\frac{1}{2}(xy+yx)$.
Oct 27, 2018 at 8:44 comment added YCor Why the tag jordan-algebra (a Jordan-algebra is a [non-necessarily-associative] commutative algebra satisfying the axiom $(xy)(xx)=x(y(xx))$)?
Oct 27, 2018 at 8:20 history asked Mark Roelands CC BY-SA 4.0