Square-root cancellation for sums of factorization functions over short intervals in function fields

Abstract

We present new estimates for sums of the divisor function, and other similar arithmetic functions, in short intervals over function fields. (When the intervals are long, one obtains a good estimate from the Riemann hypothesis.) We obtain an estimate that approaches square root cancellation as long as the characteristic of the finite field is relatively large. This is done by a geometric method, inspired by work of Hast and Matei, where we calculate the singular locus of a variety whose ${\mathbb{F}}_q$-points control this sum. This has applications to highly unbalanced moments of $L$-functions.

23 pages, updated in response to comments from referees

Cited by in corpus (3)

• Mean values of arithmetic functions in short intervals and in arithmetic progressions in the large-degree limit
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• Correlation of arithmetic functions over ${\mathbb{F}}_q[T]$