Skip to main content
Andrey Rekalo's user avatar
Andrey Rekalo's user avatar
Andrey Rekalo's user avatar
Andrey Rekalo
  • Member for 14 years, 8 months
  • Last seen more than a month ago
answered
Loading…
awarded
comment
Fastest Rolling Shape?
@Victor Protsak: Done.
revised
Loading…
revised
Loading…
revised
Introducing Cryptology to Undergraduates
added 171 characters in body
Loading…
answered
Loading…
answered
Loading…
comment
A simple infinite dimensional optimization problem
Well, actually $n+2$ $\delta$-functions are required for an arbitrary measurable space $X$ according to the theorem in my answer. A refined argument as in Noah's answer shows that when $X=[0,1]$ $n+1$ $\delta$-functions are enough.
comment
A simple infinite dimensional optimization problem
The counterexample in Noah's answer shows that only $n$ Dirac measures may not be enough.
revised
Loading…
revised
Loading…
revised
A simple infinite dimensional optimization problem
added 506 characters in body; deleted 2 characters in body
Loading…
Loading…
comment
Geodesics on a hyperbolic paraboloid
I don't understand how you obtained the geodesic equations. In general, they have the form $$\frac{d^2x^j}{dt^2}+\Gamma^{j}_{ik}\frac{dx^k}{dt}\frac{dx^i}{dt}=0$$ so the coefficients against the second derivatives should be equal to 1.
Loading…
revised
Loading…
revised
Loading…
Loading…
revised
Loading…