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arXiv · 0801.3176

Explicit calculations of automorphic forms for definite unitary groups

David Loeffler
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Abstract

I give an algorithm for computing the full space of automorphic forms for definite unitary groups over Q, and apply this to calculate the automorphic forms of level $G(Z-hat)$ and various small weights for an example of a rank 3 unitary group. This leads to some examples of various types of endoscopic lifting from automorphic forms for U_1 x U_1 x U_1 and U_1 x U_2, and to an example of a non-endoscopic form of weight (3,3) corresponding to a family of 3-dimensional irreducible l-adic Galois representations. I also compute the 2-adic slopes of some automorphic forms with level structure at 2, giving evidence for the local constancy of the slopes.

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David Loeffler. 2008-11-03. Explicit calculations of automorphic forms for definite unitary groups. https://doi.org/10.1112/s1461157000000620

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