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Questions on the calculus of variations, which deals with the optimization of functionals mostly defined on infinite dimensional spaces.

7 votes
1 answer
200 views

Prove that the maximizing point configuration on the unit circle for a Vandermonde like func...

This is probably too hard for math.stackexchange, so I migrated it here. For $\lambda_i \in S^1 \subset \mathbb{C}$, consider the functional $H(\{\lambda_1, \ldots, \lambda_n\}):= \sum_{j < k} | \lam …
John Jiang's user avatar
  • 4,354
2 votes
1 answer
816 views

Numerical or exact solution for a system of differential algebraic equations

I am looking for ways to solve the following system of boundary value implicit ODEs over the interval $t \in [0, 1]$: \begin{equation} \lambda (Fg - Gf)^3 + 4 FGfg(g-f) = 0 \\ fg(Fg-Gf) + 2FG(gf' - fg …
John Jiang's user avatar
  • 4,354
5 votes
1 answer
166 views

An extension of Hadamard maximum determinant problem

Consider the Vandermonde product $\prod_{1\le j < k \le n} |z_j - z_k|$. It is well-known that under the constraint $|z_j| \le 1$ for all $j$, the product is maximized at a picket fence configuration …
John Jiang's user avatar
  • 4,354
6 votes
0 answers
240 views

a variational problem related to weighted logarithmic capacity

Consider the following multiple contour integral: $$ \Phi_\lambda := \oint \ldots \oint \prod_{1 \le j < k \le n} (z_j^{-1} - z_k^{-1}) \prod_{j=1}^n \prod_{k=1}^n (1 - z_j x_k)^{-1} \prod_{j=1}^n z_ …
John Jiang's user avatar
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