This note answers, and generalizes, a question of Kaisa Matomäki. We show that given two cuspidal automorphic representations π1 and π2 of GL(n) over a number field F of respective conductors N1, N2, every character χ such that π1 χ ' π2 of conductor Q, satisfies the bound: Qn | N1N2. If at every finite place v, π1,v is a discrete series whenever it is ramified, then Qn divides the least common multiple [N1, N2].
|Original language||English (US)|
|Number of pages||13|
|Journal||Functiones et Approximatio, Commentarii Mathematici|
|State||Published - Sep 2021|
All Science Journal Classification (ASJC) codes
- Cusp forms
- Twist equivalence