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seen Dec 20 '13 at 15:58

Jan
30
awarded  Necromancer
Nov
23
revised Positive definite part of a symmetric matrix - or: are the positive definite matrices a retract of the set of symmetric matrices?
typos
Nov
23
answered Positive definite part of a symmetric matrix - or: are the positive definite matrices a retract of the set of symmetric matrices?
Nov
21
accepted Positive definite part of a symmetric matrix - or: are the positive definite matrices a retract of the set of symmetric matrices?
Nov
21
comment Positive definite part of a symmetric matrix - or: are the positive definite matrices a retract of the set of symmetric matrices?
This was exactly my first thought as well. The problem here is that your $A^\sharp$ depends on the choice of $G$.I do not see how this idea can be used to obtain a continuous map $A\mapsto A^\sharp$
Nov
21
asked Positive definite part of a symmetric matrix - or: are the positive definite matrices a retract of the set of symmetric matrices?
Nov
13
awarded  Self-Learner
Sep
4
awarded  Yearling
Jul
3
awarded  Citizen Patrol
Jun
21
comment If $\omega^k$ is exact, is $\omega$ exact?
For $k$ big enough, $\omega^k=0$ is always exact, isn't it?
Jun
14
answered What form of Leibniz rule is this (principal fiber bundle)?
Jun
6
asked Are any two smooth Cauchy surfaces of a globally hyperbolic manifold diffeomorphic?
May
30
comment Exactness of $\Gamma^\infty$ Functor
Thank you very much.
May
30
revised Exactness of $\Gamma^\infty$ Functor
added 536 characters in body
May
30
revised Exactness of $\Gamma^\infty$ Functor
added 2 characters in body
May
30
comment Exactness of $\Gamma^\infty$ Functor
See, the point is that I cannot spend the time and space to prove it myself at the moment.
May
30
asked Exactness of $\Gamma^\infty$ Functor
Dec
14
comment Spectral measures
Because I am actually working on a proof for the spectral theorem. Maybe I should be more precise here. What we can use is the continuous functional calculus (including the spectral mapping theorem) as well as the bounded Borel functional calculus for bounded normal operators.
Dec
14
asked Spectral measures
Dec
6
awarded  Commentator