Additive twists of Fourier coefficients of symmetric-square lifts
  We study the sum of additively twisted Fourier coefficients of a symmetric-square lift of a Maass form invariant under the full modular group. Our bounds are uniform in terms of the spectral parameter of the Maass form, as well as in terms of the additive twist. 
Xiaoqing Li and Matthew P. Young
math.NT