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Eigenvalues in the large sieve inequality, II

Olivier Ramaré (2010)

Journal de Théorie des Nombres de Bordeaux

We explore numerically the eigenvalues of the hermitian form q Q a mod * q n N ϕ n e ( n a / q ) 2 when N = q Q φ ( q ) . We improve on the existing upper bound, and produce a (conjectural) plot of the asymptotic distribution of its eigenvalues by exploiting fairly extensive computations. The main outcome is that this asymptotic density most probably exists but is not continuous with respect to the Lebesgue measure.

Fejér–Riesz factorizations and the structure of bivariate polynomials orthogonal on the bi-circle

Jeffrey S. Geronimo, Plamen Iliev (2014)

Journal of the European Mathematical Society

We give a complete characterization of the positive trigonometric polynomials Q ( θ , ϕ ) on the bi-circle, which can be factored as Q ( θ , ϕ ) = | p ( e i θ , e i ϕ ) | 2 where p ( z , w ) is a polynomial nonzero for | z | = 1 and | w | 1 . The conditions are in terms of recurrence coefficients associated with the polynomials in lexicographical and reverse lexicographical ordering orthogonal with respect to the weight 1 4 π 2 Q ( θ , ϕ ) on the bi-circle. We use this result to describe how specific factorizations of weights on the bi-circle can be translated into identities relating...

Generalized interpolation in the unit ball.

Nicolas Marco (2001)

Publicacions Matemàtiques

We study a generalized interpolation problem for the space H∞(B2) of bounded homomorphic functions in the ball B2. A sequence Z = {zn} of B2 is an interpolating sequence of order 1 if for all sequence of values wn satisfying conditions of order 1 (that is discrete derivatives in the pseudohyperbolic metric are bounded) there exists a function f ∈ H∞(B2) such that f(zn) = wn. These sequences are characterized as unions of 3 free interpolating sequences for H∞(B2) such that all triplets of Z made...

Interpolating sequences and the Nevanlinna Pick problem.

Arne Stray (1991)

Publicacions Matemàtiques

The extremal solutions to the Nevanlinna Pick problem are studied. If there is more than one solution, Nevanlinna showed that all extremal solutions are inner functions. With some extra information on the interpolation data we find that the extremal solutions are Blaschke products whose zeroes form a finite union of interpolating sequences.

Interpolation of bounded sequences

Francesc Tugores (2010)

Czechoslovak Mathematical Journal

This paper deals with an interpolation problem in the open unit disc 𝔻 of the complex plane. We characterize the sequences in a Stolz angle of 𝔻 , verifying that the bounded sequences are interpolated on them by a certain class of not bounded holomorphic functions on 𝔻 , but very close to the bounded ones. We prove that these interpolating sequences are also uniformly separated, as in the case of the interpolation by bounded holomorphic functions.

Interpolation operators on the space of holomorphic functions on the unit circle

Josef Kofroň (2001)

Applications of Mathematics

The aim of the paper is to get an estimation of the error of the general interpolation rule for functions which are real valued on the interval [ - a , a ] , a ( 0 , 1 ) , have a holomorphic extension on the unit circle and are quadratic integrable on the boundary of it. The obtained estimate does not depend on the derivatives of the function to be interpolated. The optimal interpolation formula with mutually different nodes is constructed and an error estimate as well as the rate of convergence are obtained. The general...

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