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 1h comment Golden Ratio & Fibonacci - Two-Beamed problem by Charles de Gaulle (13 unit squares) I voted to close as off-topic but want to add that the question would probably not be well received at math.stackexchange in its current form. At least state the whole question in the text. Apr 29 comment Which algorithm is most efficient for a specific QP problem Why using coordinate descent when you have the full gradient with similar cost? Try Nesterov's accelerated gradient and also check out projected Newton methods. If you want to use available toolboxes, search for "bound constrained convex quadratic" or "box" instead of "bound". Apr 26 answered Fréchet L-Spaces Apr 11 revised Is $\max_{\|x\|_p=\|y\|_p=1} |\langle x, Ay\rangle|$ equivalent to $\max_{\|x\|_p=|} |\langle x, Ax\rangle|$ for symmetric $A$ & $p\geq 2$? edited body Apr 11 revised Is $\max_{\|x\|_p=\|y\|_p=1} |\langle x, Ay\rangle|$ equivalent to $\max_{\|x\|_p=|} |\langle x, Ax\rangle|$ for symmetric $A$ & $p\geq 2$? edited body Mar 4 comment Shape whose translated and scaled copies are closed under intersection Don't know if these count as a shapes but this also holds for single points, lines and line segments. Mar 3 comment Extreme couplings Relevant answer here: mathoverflow.net/a/152271/9652 Mar 3 comment Extreme couplings In ther discrete case the buzzword is "Birkhoff polytope". Mar 3 comment Completion of spaces of measures w.r.t. weak norms @PassingThru Ok, thanks for clarifying. As much as I try to love these two volumes of Bogachev, I always struggle with the notation and diversity of concepts in there. Mar 2 comment Bounds on the curvature of a sequence of convex functions I don't think that there is some simple control of this ratio. You could have some $f_n$ that approach a function with a non-differentiable kink at the minimum, even with fixed value at the minimum (some scaled and translated version of $\sqrt{x^2+1/n}$). Mar 2 comment Completion of spaces of measures w.r.t. weak norms @PassingThru As far as I see, the norm $\|\sigma\|_0^*$ is exactly as Bogachev defines it in §8.10 for the difference of two Borel probability measures with finite first moments. In fact he has another Kantorovich-Rubinshtein norm in §8.3 but I thought that I could go with this setting as well. Mar 2 comment Completion of spaces of measures w.r.t. weak norms @TomekKania And does the completion of measure space w.r.t. the Fortet-Mourier norm also has a name or a different characterization in that community? Or would that make a separate question? Mar 1 comment Completion of spaces of measures w.r.t. weak norms Thanks! I really forgot to check your book (which I read some years ago) - also the pointer to Lipschitz-free spaces sounds interesting. Mar 1 accepted Completion of spaces of measures w.r.t. weak norms Mar 1 asked Completion of spaces of measures w.r.t. weak norms Feb 26 comment Alternative representation of $C_c(X)$ as inductive limit Oops, yes $C(X;K_{n+1})$ is what I meant. For question 2 I have no idea. Feb 26 comment Alternative representation of $C_c(X)$ as inductive limit I see not much difference in your construction. Let me say it this way: Since $C(K_n)$ isometrically embeds in $C(X;K_{n+1})$ (as you noted) the "original construction" is the strict inductive limit of the $C(X;K_n)$ while your construction is the strict inductive limit of the $C(K;K_{n+1})$… Feb 24 comment A problem on real valued functions in $\mathbb{R}^2$ with least variation I doubt that this will be optimal or almost optimal up to a constant: Consider a wide and flat rectangle-like $\Omega$ and boundary values that are close to one in the middle the short edges and zero along the long edges. The proposed approach by scaling introduce long "edges" in the interior of $\Omega$ while $TV$ would favor short edges… Feb 24 revised A problem on real valued functions in $\mathbb{R}^2$ with least variation added 21 characters in body Feb 23 comment an inverse problem related to gaussian integral @yimin Sounds strange at first sight, that this may well be possible (note that $f_T(x)$ can be an analytic function in $x$ and $T$ and hence, determined if known on a set with some cluster point). More to the OP: I don't know the answer but I vaguely remember that the book The One-Dimensional Heat Equation by Cannon is a great source for such questions.