The mean square of the product of the Riemann zeta-function and a Dirichlet polynomial in the critical strip

Abstract: We refine a previous work of K. Matsumoto and H. Ishikawa, obtaining an asymptotic formula for the mean square of the product of the Riemann zeta-function and a Dirichlet polynomial in the critical strip (1/4<$\sigma$<1/2), by obtaining an explicit formula of Atkinson type for its error term. This work is closely related to the generalized Dirichlet divisor problem. The form of these formulas is akin to, yet more complex than, Voronoi's formulas in the divisor problem.