Shifted Convolution Sum for $GL(3) \times GL(2)$ with Weighted Average
In this paper, we will prove the non-trivial bound for the weighted average version of shifted convolution sum for $GL(3)\times GL(2)$, i.e. for any $\epsilon >0$ and $X^{1/4+\delta} \leq H \leq X$ with $\delta >0$, \[ \frac{1}{H}\sum_{h=1}^\infty \lambda_f(h) V\left( \frac{h}{H}\right)\sum_{n=1}^\infty \lambda_{\pi}(1,n) \lambda_g (n+h) W\left( \frac{n}{X} \right)\ll X^{1-\delta+\epsilon} \] where $V,W$ are smooth compactly supported funtions, $\lambda_f(n), \lambda_g(n)$ and $\lambda_{\pi}(1,n)$ are the normalized n-th Fourier coefficients of $SL(2,\mathbb{Z})$ Hecke-Maass cusp forms $f,g$ and $SL(3,\mathbb{Z})$ Hecke-Maass cusp form $\pi$, respectively.