Abstract :
This paper deals with the Cesàro means of conjugate Jacobi series introduced by Muckenhoupt and Stein and Li. The exact estimates of the norms of the conjugate (C, δ) kernel for 0⩽δ⩽α+12 are obtained. It is proved that whenδ>α+12 , the (C, δ) means of the conjugate Jacobi expansion of a functionfconverges almost everywhere to its (Jacobi) conjugate function and so does the (C, α+12) means at the critical index under the criterius of Lebesgue type by use of the equiconvergence theorem.
