Angelo Lucia
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 Apr 8 answered Meaning of representation Apr 4 comment Expanding information capacity of Gaussian Channel Could you please clarify your notation? I suppose $I(\cdot; \cdot)$ is the mutual information, and $h(\cdot)$ is the Shannon entropy, right? Also, what are $X$, $Y$ and $Z$? Apr 4 revised Weak star limit language and notation Apr 4 comment Weak star limit Sorry, I do not understand your question: what is $k$ in your definition? You defined $A^\epsilon$, what is $A_n$? (Is this homework?) Apr 4 suggested approved edit on Weak star limit Apr 3 comment Exercise Functional Analysis Also, you should really have a look at en.wikipedia.org/wiki/Derivation_(abstract_algebra) Apr 3 awarded Commentator Apr 3 comment Exercise Functional Analysis It seems to me that if you define an arbitrary value for $\mathcal O(x)$, then you can extend the operator uniquely to polynomials (and then by density to differentiable functions). Oct 20 comment Positivity of the anti-commutator of two positive operators implies commutativity? Yes, indeed. The reason I was expecting them to commute is that if we call $P_B$ the ortogonal projector onto the kernel of $B$, then the fact that $\{ A, B \} \ge 0$ do imply that $A$ commutes with $P_B$. (in your example, this is trivial, but is not in general) Oct 19 comment Positivity of the anti-commutator of two positive operators implies commutativity? Nice! I was pretty convinced that it was true. Oct 19 accepted Positivity of the anti-commutator of two positive operators implies commutativity? Oct 19 revised Positivity of the anti-commutator of two positive operators implies commutativity? just reformulating in proper English Oct 19 comment Positivity of the anti-commutator of two positive operators implies commutativity? In your examples $A$ and $B$ are not Hermitian, and thus not positive, at least under one definition of positivity. Which is probably the most common. Where you thinking of the generalization of positivity for non hermitian matrices? Oct 19 asked Positivity of the anti-commutator of two positive operators implies commutativity? Apr 23 accepted Laplace transform with (real) compact support Apr 18 asked Laplace transform with (real) compact support Aug 30 comment Functional from $(0,+\infty)$ to $L^p(\mathbb R)$ It's ok: it was probably the only possible interpretation, and in fact looks like nobody misunderstood what you meant. Aug 29 comment Functional from $(0,+\infty)$ to $L^p(\mathbb R)$ I am trying to understand how $f^r$ is defined: maybe you wanted to say that for every $r \in (0, \infty)$, $f^r$ is in $L^p(\mathbb{R})$. That's different from saying that for every $r$ we have $f^r : (0,\infty) \to L^p(\mathbb{R})$. Aug 26 accepted Positive functionals on $\ell^\infty$ Aug 24 revised Positive functionals on $\ell^\infty$ feel free to use AC