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bio website www-ian.math.uni-magdeburg.de/…
location Magdeburg, Germany
age 31
visits member for 3 years, 8 months
seen 2 days ago

I am an Australian mathematician.


Aug
25
revised The integral of the mean curvature vector over a closed immersed surface
clarification
Aug
25
comment The integral of the mean curvature vector over a closed immersed surface
@Willie I meant by this that $\Sigma$ has a Riemannian structure induced by $f$. I shall make it more explicit.
Aug
25
comment The integral of the mean curvature vector over a closed immersed surface
@anon Since I can't see the proof, it may also be that they are assuming the surface is embedded and has genus 0. Sometimes this went without saying.
Aug
25
comment The integral of the mean curvature vector over a closed immersed surface
@anon My university doesn't have a subscription to that journal, and it would be nice to see what kind of conditions they impose on $f$ and $\Sigma$ to obtain their result.
Aug
25
asked The integral of the mean curvature vector over a closed immersed surface
Aug
15
awarded  Excavator
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Didier I've been thinking of $f\in C^1$.
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Olivier I see that this is my miscommunication. All this time I have been 'explaining' my statement in my first comment. I completely ignored the OP's definition.
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Olivier Let $f$ be your function. $|f'(\epsilon)| > c\epsilon^{-1}$ for some finite $c$.
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Olivier This just bounds the function itself at zero. The derivative is still unbounded in any open interval containing zero, and since by hypothesis $f$ is differentiable, zero cannot be in $[a,b]$.
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Olivier Not really, the derivative of that function is bounded on any closed interval not containing zero, and zero is not allowed in the interval because the function is not differentiable at zero. I think you may be confused.
Aug
11
comment derivative must be bounded on interior for a differentiable function on a closed interval
@Olivier Sometimes $f$ being differentiable is shorthand for $f\in C^1$, and if $f\in C^1$ over a closed interval, then $f'\in C^0$ and is bounded.
Jul
20
comment Nonlinear Fubini-Tonelli?
@Shai In this question let's leave it at $f(y)$, since that's where all the discussion has headed. I had $f(x,y)$ in mind, which one could probably guess from my comments, but my mistake for not writing it correctly in the first place :).
Jul
20
comment Nonlinear Fubini-Tonelli?
This is certainly related. One can use several standard techniques to estimate the integral (from above and below) and then the cases of equality gives expressions equivalent to that above in special cases. But Fubini-Tonelli is fundamentally an equality. Still, thanks for the answer. +1
Jul
20
asked Nonlinear Fubini-Tonelli?
Jul
8
answered Intuitive interpretation of the Laplacian
Jul
4
comment Mathematics necessary for a Master's degree in CS
Algebraic geometry? Really?
Jul
1
answered An integral identity
Jul
1
comment An integral identity
Would you please include a description of the "brute-force" method?
Jul
1
comment Fourier series at discontinuities
@Hans I started writing my answer below before looking at the paper, but did have a vague recollection of it. It turns out that in the end, the argument is identical to that found in Chernoff's paper. Do you know if this is the original source of the argument?