Cohomology of discrete groups and Dirichlet series connected with Jacquet–Langlands cusp Forms

Using an isomorphism of Eichler–Shimura type, the algebraicity is proved, up to a common constant factor, of the values in the center of the critical strip of the $L$-series connected with a “new” modular cusp form on $G_A$ for an imaginary quadratic field twisted with arbitrary Dirichlet characters of this field.
Bibliography: 8 titles.