Walter Trebels

collaborators

2 papers

math.CV2025

Extremal polynomials for the Rogosinski--Szegő estimates of the third coefficient of nonnegative sine polynomials

Dmitriy Dmitrishin, Alexander Stokolos, Walter Trebels

In the class of normalized sine-polynomials $S (t),$ non-negative on $[0, π],$ W.Rogosinski and G.Szegő 1950 considered a number of extremal problems and proved, among other things,…

math.CA2024

Extremizers for the Rogosinski-Szegö estimate of the second coefficient in nonnegative sine polynomials

Dmitriy Dmitrishin, Alexander Stokolos, Walter Trebels

For the class of sine polynomials $b_{1} sin t + b_{2} sin 2 t + ... + b_{N} sin N t, (b_{N} \neq = 0),$ which are nonnegative on $(0, π)$ , W. Rogosinski and G. Szegö derived, among other things, ex…