“…The Birch sums (1.2) are examples of ℓ-adic trace functions over finite fields. These trace functions have been extensively studied in a series of recent works by Fouvry, Kowalski, and Michel [4], [5], [6], Fouvry, Kowalski, Michel, Raju, Rivat, and Soundararajan [7], Kowalski and Sawin [11], [12], and Perret-Gentil [16], [17]. Our results can be generalized to other types of trace functions that are attached to certain coherent families of ℓ-adic sheaves (in the sense given by Perret-Gentil [16]), if their short sums satisfy a bound similar to (1.8).…”