Low moments of automorphic random multiplicative function sums

Abstract

We determine the order of the low moments of partial sums of random multiplicative functions associated with Euler products of bounded degree whose unitary local parameters satisfy a prime-square cancellation condition, thereby generalizing Harper's seminal work. The result applies to irreducible compact-group representations of unitary or symplectic type, including the higher-rank Sato--Tate model $SU(d)$ and the odd symmetric-power Sato--Tate model $\operatorname{Sym}^{m}SU(2)$.