The $D^6{R}^4$ interaction as a Poincaré series, and a related shifted convolution sum

Kim Klinger-Logan, Stephen D. Miller, Danylo Radchenko

We complete the program, initiated in a 2015 paper of Green, Miller, and Vanhove, of directly constructing the automorphic solution to the string theory $D^6{R}^4$ differential equa…