An Inequality for Trigonometric Polynomials

• Autorzy: N. K. Govil , Mohammed A. Qazi , Qazi I. Rahman
• Języki publikacji: EN

Abstrakty

EN

The main result says in particular that if $t(ζ):= ∑_{ν=-n}ⁿ c_ν e^{iνζ}$ is a trigonometric polynomial of degree n having all its zeros in the open upper half-plane such that |t(ξ)| ≥ μ on the real axis and cₙ ≠ 0, then |t'(ξ)| ≥ μn for all real ξ.

Kategorie tematyczne

• 30D15: Special classes of entire functions and growth estimates
• 41A17: Inequalities in approximation (Bernstein, Jackson, Nikol\cprime ski{\u\i}-type inequalities)

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Bulletin of the Polish Academy of Sciences. Mathematics
• Rocznik: 2012
• Tom: 60
• Numer: 3
• Strony: 241-247

Daty

wydano

2012

Twórcy

autor

N. K. Govil

• Department of Mathematics, Auburn University, Auburn, AL 36849-5310, U.S.A.

autor

Mohammed A. Qazi

• Department of Mathematics, Tuskegee University, Tuskegee, AL 36088, U.S.A.

autor

Qazi I. Rahman

• Département de Mathématiques et de Statistique, Université de Montréal, Montréal, H3C 3J7, Canada

Identyfikatory

DOI

10.4064/ba60-3-4