Erdős Problem #1130 — Nodes maximizing local Lebesgue minima

For x1,…,xn∈[−1,1]x_1,\ldots,x_n\in [-1,1] let lk(x)=∏i≠k(x−xi)∏i≠k(xk−xi),l_k(x)=\frac{\prod_{i\neq k}(x-x_i)}{\prod_{i\neq k}(x_k-x_i)}, which are such that lk(xk)=1l_k(x_k)=1 and lk(xi)=0l_k(x_i)=0 for i≠ki\neq k. Let x0=−1x_0=-1 and xn+1=1x_{n+1}=1 and Υ(x1,…,xn)=min⁡0≤i≤nmax⁡x∈[xi,xi+1]∑k∣lk(x)∣.\Upsilon(x_1,\ldots,x_n)=\min_{0\leq i\leq n}\max_{x\in[x_i,x_{i+1}]} \sum_k \lvert l_k(x)\rvert. Is it true that Υ(x1,…,xn)≪log⁡n?\Upsilon(x_1,\ldots,x_n)\ll \log n? Describe which choice of xix_i maximise Υ(x1,…,xn)\Upsilon(x_1,\ldots,x_n).

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