bio | website | regularize.wordpress.com |
---|---|---|
location | Braunschweig, Germany | |
age | 36 | |
visits | member for | 4 years, 7 months |
seen | 3 hours ago | |
stats | profile views | 1,909 |
Professor at TU Braunschweig.
Area: Inverse problems, regularization theory, applied functional analysis, mathematical image processing.
Dec 21 |
comment |
Open problems in compressed sensing
One thing is that it makes a huge difference if one answers this question as a mathematician or as an engineer. Well, of course this is site for mathematics but the idea of compressed sensing is really a practical one: get information about a high dimensional object that lives in lower dimensional but nonlinear subspace from few measurements. The meaning of all ingredients is debatable here and varies a lot from problem to problem. Hence one open problem is to find the right mathematical formulation of the problem... |
Dec 19 |
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Image of (right) inverse trace map $\xi\colon H^{\frac 12}(\partial\Omega) \to H^1(\Omega)$ dense in $H^1(\Omega)$?
Ok, right - I thought that I had a basic misconception about the problem… |
Dec 19 |
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journal to submit mathematic books' review
The German "Mathematische Semesterberichte" publishes such reviews (probably only in German). |
Dec 19 |
reviewed | Close How to construct a graph with arbitrarily large girth and large chromatic number? |
Dec 19 |
reviewed | Leave Open Image of (right) inverse trace map $\xi\colon H^{\frac 12}(\partial\Omega) \to H^1(\Omega)$ dense in $H^1(\Omega)$? |
Dec 19 |
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Image of (right) inverse trace map $\xi\colon H^{\frac 12}(\partial\Omega) \to H^1(\Omega)$ dense in $H^1(\Omega)$?
Isn't solving the respective Dirichlet problem saying that the image contains $H^{3/2}$? |
Dec 16 |
reviewed | Close Alexander duality theorem |
Dec 11 |
revised |
What is an extragradient method?
corrected spelling |
Dec 10 |
answered | Galerkin Projection on Integral Operators |
Dec 10 |
answered | What is an extragradient method? |
Dec 7 |
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Banach space of discontinuous functions(Killing continuous functions)
"Appropriate quotient space" Do you have an idea how this space looks like (or how the space which you divide by)? I guess the quotient contains all characteristic functions of all points and then it wouldn't be separable in the first norm. The second norm looks pretty weired to me… |
Dec 4 |
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$Ax=b$ in a function space
I am not sure what you are after. Do you want to show that the solution depends continuously on the matrix? Are you especially interested in the case where $A$ gets singular? |
Nov 27 |
awarded | Notable Question |
Nov 25 |
accepted | Geometric measures different from Hausdorff |
Nov 25 |
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Reference for a strong intermediate value theorem for measures
Actually, your statement is not strictly stronger than the result the OP is asking for since he wants the sets $S_t$ to be nested. |
Nov 20 |
reviewed | Leave Open “Almost” zeta function |
Nov 19 |
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Removing constraints in convex optimization
Well, ehm, actually I don't see it either… Adapted my answer which is only a "partial answer" now… |
Nov 19 |
revised |
Removing constraints in convex optimization
Extended and corrected |
Nov 19 |
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What's the idea behind various equivalent norms on Besov spaces $B^{s}_{p,q}$?
Another book that is quite detailed is Runst and Sickel's Sobolev Spaces of Fractional Order, Nemytskij Operators, and Nonlinear Partial Differential Equations. However, I guess for the equivalence of the norms they refer to Triebel… |
Nov 19 |
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Geometric measures different from Hausdorff
Thanks a lot for the answer, especially for pointin to Frostman's lemma, densities and the example where $H^m(A)>0$ and $G_m(A) = 0$. This is exactly in the direction I was hoping. If you had additonally some concrete examples where Hausdorff, Dyadic and Spherical Measure differ I would accept and cash the bounty right away! |