The tower property on the genericity of global theta lifts

In this paper, we examine the tower property concerning the genericity of global theta lifts between various classical groups, drawing inspiration from Rallis’ tower property. By exploring the relationship between the analytic properties of $L$-functions and special Bessel and Fourier-Jacobi periods, we demonstrate that the first occurrence of global theta lifts between dual reductive groups preserves genericity. As an application, we establish the global Gan-Gross-Prasad conjecture for ${\text{SO}}_{2n+1}\times {\text{SO}}_2$ under the assumption that ${\text{SO}}_2$ is split and its representation is trivial.