The Nevai Condition

نویسندگان

  • Jonathan Breuer
  • Barry Simon
چکیده

We study Nevai’s condition that for orthogonal polynomials on the real line, Kn(x, x0)Kn(x0, x0)−1 dρ(x) → δx0 , where Kn is the Christoffel–Darboux kernel. We prove that it holds for the Nevai class of a finite gap set uniformly on the spectrum, and we provide an example of a regular measure on [−2,2] where it fails on an interval.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Critical Lieb-thirring Bounds in Gaps and the Generalized Nevai Conjecture for Finite Gap Jacobi Matrices

We prove bounds of the form ∑ e∈I∩σd(H ) dist ( e, σe(H ) )1/2 ≤ L-norm of a perturbation, where I is a gap. Included are gaps in continuum one-dimensional periodic Schrödinger operators and finite gap Jacobi matrices, where we get a generalized Nevai conjecture about an L1-condition implying a Szegő condition. One key is a general new form of the Birman-Schwinger bound in gaps.

متن کامل

Asymptotics of derivatives of orthogonal polynomials on the unit circle

We show that ratio asymptotics of orthogonal polynomials on the circle imply ratio asymptotics for all their derivatives. Moreover, by reworking ideas of P. Nevai, we show that uniform asymptotics for orthogonal polynomials on an arc of the unit circle imply asymptotics for all their derivatives. Let be a …nite positive Borel measure on the unit circle (or [0; 2 ]). Let f'ng denote the orthonor...

متن کامل

Equivalence Classes of Block Jacobi Matrices

The paper contains two results on the equivalence classes of block Jacobi matrices: first, that the Jacobi matrix of type 2 in the Nevai class has An coefficients converging to 1, and second, that under an L1-type condition on the Jacobi coefficients, equivalent Jacobi matrices of types 1, 2 and 3 are pairwise asymptotic.

متن کامل

On a Conjecture of Nevai

It is shown that a conjecture concerning the derivatives of orthogonal polynomials, proved by Nevai in 1990 for generalized Jacobi weights, holds for doubling weights as well.

متن کامل

On Erdélyi-magnus-nevai Conjecture for Jacobi Polynomials

T. Erdélyi, A.P. Magnus and P. Nevai conjectured that for α, β ≥ − 1 2 , the orthonormal Jacobi polynomials P (α,β) k (x) satisfy the inequality max x∈[−1,1] (1− x) 1 2 (1 + x) 1 2 ( P (α,β) k (x) )2 = O (

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008