bio | website | regularize.wordpress.com |
---|---|---|
location | Braunschweig, Germany | |
age | 36 | |
visits | member for | 4 years, 4 months |
seen | 3 hours ago | |
stats | profile views | 1,819 |
Professor at TU Braunschweig.
Area: Inverse problems, regularization theory, applied functional analysis, mathematical image processing.
Nov 19 |
comment |
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 |
comment |
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! |
Nov 18 |
reviewed | Leave Open How to prove that a kernel is positive definite? |
Nov 17 |
answered | Removing constraints in convex optimization |
Nov 14 |
reviewed | Approve Graph automorphism that swaps two pairs of nodes |
Nov 14 |
answered | Standard names and methods for this type of fitting minimization |
Nov 14 |
comment |
Noncommutative version of Littlewood's First Principle
While the title sounds interesting to me, I have to admit that I don't have any idea what this "noncommutative setting" you are talking about may be, let alone what an analog of Littlewood's principle may be. |
Nov 13 |
comment |
Does the boundary of a convex body contain a regular planar pentagon?
Does a convex body need to have nonempty other interior? Otherwise the answer is no. |
Nov 12 |
revised |
Is the boundary $\partial S$ analogous to a derivative?
Corrected typos. Extended answer a bit. |
Nov 9 |
comment |
Area of the minimal surface of a non-planar quadrilateral in 3d
Regarding your other comment: I thought 'minimal surface' would mean 'surface of minimal area' but probably there are some local minima (whatever this means in this context)? |
Nov 9 |
comment |
Area of the minimal surface of a non-planar quadrilateral in 3d
A formula in elliptic functions or another non-elementary integral would be OK. In the end I would be happy with a simple numerical method to calculate the value. |
Nov 7 |
asked | Area of the minimal surface of a non-planar quadrilateral in 3d |
Nov 5 |
reviewed | Close How to solve the opposite of max flow problem? |
Nov 4 |
reviewed | Leave Open Difference Quotients Evans |
Nov 4 |
reviewed | Leave Closed Estimating a sum |
Nov 4 |
answered | Maximum of a mollified/convolution function |
Nov 3 |
comment |
Maximum of a mollified/convolution function
Questions like this have been treated in the concept of "scale space methods" in mathematical image processing about 15 or 20 years ago where one was interested in the question: How many local minima and maxima survive after convolution and can new local minima or maxima be created? Unfortunately I forgot about the exact references but one result was along the lines: If you take a scale kernel $\phi_t(x) = 1/t\phi(x/t)$ and require that the number of local maxima and minima of $\phi_t\ast f$ is decaying with $t$, and some more hypotheses, then $\phi$ is a Gaussian… |
Oct 31 |
reviewed | Leave Closed A metric on $S^{2}$ |
Oct 30 |
comment |
numerical solver for stochastic optimal control problems
I think this is better suited for computational science over at scicomp.stackexchange.com. |
Oct 29 |
comment |
Central-Slice-Theorem Analogue for Wavelet Transforms?
Why do you think that such analog should exist? The 2D Fourier transform and the 2D wavelet transform are not really similar things. You are aware of the fact that the wavelet transform results in a function that lives on a different set, right? Meanwhile, you may be interested in the ridgelet transform which combines the Radon and the wavelet transform. |