Approximation by Shifts of Compositions of Dirichlet L-Functions with the Gram Function

In this paper, a joint approximation of analytic functions by shifts of Dirichlet L-functions L ( s + i a 1 t τ , χ 1 ) , … , L ( s + i a r t τ , χ r ) , where a 1 , … , a r are non-zero real algebraic numbers linearly independent over the field Q and t τ is the Gram function, is considered. It is proved that the set of their shifts has a positive lower density.