Bos, Leonard PeterLevenberg, NormOrtega Cerdà, Joaquim2021-11-252021-11-252020-11-020176-4276https://hdl.handle.net/2445/181476We show that the problem of finding the measure supported on a compact set $K\subset \C$ such that the variance of the least squares predictor by polynomials of degree at most $n$ at a point $z_0\in\C^d\backslash K$ is a minimum, is equivalent to the problem of finding the polynomial of degree at most $n,$ bounded by 1 on $K,$ with extremal growth at $z_0.$ We use this to find the polynomials of extremal growth for $[-1,1]\subset \C$ at a purely imaginary point. The related problem on the extremal growth of real polynomials was studied by Erd\H{o}s (Bull Am Math Soc 53:1169-1176, 1947).23 p.application/pdfeng(c) Springer Science + Business Media, 2020Desigualtats (Matemàtica)Teoria de l'aproximacióFuncions de variables complexesInequalities (Mathematics)Approximation theoryFunctions of complex variablesinfo:eu-repo/semantics/article7028472021-11-25info:eu-repo/semantics/openAccess