6533b857fe1ef96bd12b4365

RESEARCH PRODUCT

On an Inequality for Trigonometric Polynomials In Several Variables

Helmut Rüssmann

subject

Classical orthogonal polynomialsDiscrete mathematicsPure mathematicssymbols.namesakePythagorean trigonometric identityOrthogonal polynomialsDifferentiation of trigonometric functionssymbolsTrigonometric substitutionTrigonometric integralTrigonometric polynomialProofs of trigonometric identitiesMathematics

description

Publisher Summary This chapter presents trigonometric polynomials in n variables. Using the methods of approximation theory, an inequality can be extended to almost periodic functions and to still more general classes of functions as in the case for Bohr's inequality. However, no analogous result exists in the case of two variables. For the solution of problems containing small divisors, the estimate has to be completed by theorems concerning the best approximation of holomorphic functions by trigonometric polynomials in polystrips. The chapter also presents equations to provide an estimate for a differential operator.

https://doi.org/10.1016/b978-0-12-574249-8.50030-4