Abstract
Refined direct and converse theorems of trigonometric approximation are proved in the variable exponent Lebesgue spaces with weights satisfying some Muckenhoupt Ap
-condition. As a consequence, the refined versions of Marchaud and its converse inequalities are obtained.
By some estimates for the variable fractional maximal operator, the authors prove that the fractional integral operator is bounded and satisfies the weak-type inequality on variable exponent Lebesgue spaces.