In mathematics, a Szegő polynomial is one of a family of orthogonal polynomials for the Hermitian inner product ⟨ f | g ⟩ = ∫ − π π f g ¯ d μ {\displaystyle \langle f|g\rangle =\int _{-\pi }^{\pi }f{\overline {g}}\,d\mu } where dμ is a given positive measure on [−π, π]. Wikipedia