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seen Dec 13 at 23:37

Aug
18
revised An argument to prove asymptotic expansions
corrected typo
Aug
18
asked An argument to prove asymptotic expansions
Aug
18
comment Standard terminology for the relation between $A$ and $B$ if $B= Q^t A P$?
Yes, thanks for writing up these clarifications. But what these "conjugations" actually mean, was more or less clear to me. I just wanted to know if the case under question has a standard name. I'm trying to write a proof where I have to change a lot of times coordinates in V and W in suitable ways, and I wanted to say: at every step I get a matrix which is "..." to the previous, using a standard term. Maybe i should just write "equivalent" (after defining what I mean).
Aug
18
accepted Inequality for a selfadjoint operator on Hilbert space
Aug
18
comment Inequality for a selfadjoint operator on Hilbert space
I like this point of view very much. Thanks. I think a canonical reference for the spectral theorem you cite could be Theorem VIII.4 in the first Volume of Reed-Simon.
Aug
18
comment Standard terminology for the relation between $A$ and $B$ if $B= Q^t A P$?
@M Turgeon. Yes, thanks, I forgot to write it.
Aug
18
revised Standard terminology for the relation between $A$ and $B$ if $B= Q^t A P$?
added 16 characters in body
Aug
17
asked Standard terminology for the relation between $A$ and $B$ if $B= Q^t A P$?
Aug
17
comment Inequality for singular values
ok, I got it: if $u$ is an eigenvector of $A^TA$ then $Au$ is an eigenvector of $AA^T$ with same eigenvalue, and viceversa.
Aug
17
comment Inequality for singular values
Why $A^T A$ and $A A^T$ have the same eigenvalues?
Aug
17
comment Inequality for singular values
Thanks for this fast answer. As far as I understand the same reasoning doesn't work if $A,B$ are symmetric and if the $\mu_i$'s denote eigenvalues instead of singular values. Am I wrong? Do in that case the inequalities not hold?
Aug
17
revised Inequality for singular values
deleted 2 characters in body
Aug
17
revised Inequality for a selfadjoint operator on Hilbert space
added tag
Aug
17
asked Inequality for singular values
Aug
17
awarded  Teacher
Aug
16
revised Inequality for a selfadjoint operator on Hilbert space
added tag spectral theory
Aug
16
comment Inequality for a selfadjoint operator on Hilbert space
@timur: I edited the answer to clarify.
Aug
16
revised Inequality for a selfadjoint operator on Hilbert space
clarification to firste equality after comments of Byron Schmuland and timur.
Aug
16
revised Inequality for a selfadjoint operator on Hilbert space
deleted 65 characters in body
Aug
16
comment Inequality for a selfadjoint operator on Hilbert space
I use that $1_{[b,\infty)}(T)$ is selfadjoint and that it is equal to its square. Therefore both the things you wrote are correct in my opinion.