Truncation of Eisenstein series (Q1935346)

The authors built upon the first author's previous work on truncation of Eisenstein series [Clay Math. Proc. 13, 309--331 (2011; Zbl 1242.22025)], and obtain an explicit formula for the truncation of a general Eisenstein series (Proposition 13). From this explicit formula they derive a generalization of the Maass-Selberg relation on inner product of truncated Eisenstein series, and in particular they recover Arthur's asymptotic inner product formula. The proof is a smart argument based on some combinatorial lemmas.