Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Automorphic forms for some even unimodular lattices
AU - Dummigan, Neil
AU - Fretwell, Dan
PY - 2021/4/30
Y1 - 2021/4/30
N2 - We look at genera of even unimodular lattices of rank 12 over the ring of integers of Q(5) and of rank 8 over the ring of integers of Q(3), using Kneser neighbours to diagonalise spaces of scalar-valued algebraic modular forms. We conjecture most of the global Arthur parameters, and prove several of them using theta series, in the manner of Ikeda and Yamana. We find instances of congruences for non-parallel weight Hilbert modular forms. Turning to the genus of Hermitian lattices of rank 12 over the Eisenstein integers, even and unimodular over Z, we prove a conjecture of Hentschel, Krieg and Nebe, identifying a certain linear combination of theta series as an Hermitian Ikeda lift, and we prove that another is an Hermitian Miyawaki lift.
AB - We look at genera of even unimodular lattices of rank 12 over the ring of integers of Q(5) and of rank 8 over the ring of integers of Q(3), using Kneser neighbours to diagonalise spaces of scalar-valued algebraic modular forms. We conjecture most of the global Arthur parameters, and prove several of them using theta series, in the manner of Ikeda and Yamana. We find instances of congruences for non-parallel weight Hilbert modular forms. Turning to the genus of Hermitian lattices of rank 12 over the Eisenstein integers, even and unimodular over Z, we prove a conjecture of Hentschel, Krieg and Nebe, identifying a certain linear combination of theta series as an Hermitian Ikeda lift, and we prove that another is an Hermitian Miyawaki lift.
KW - Algebraic modular forms
KW - Even unimodular lattices
KW - Hermitian modular forms
KW - Hilbert modular forms
KW - Theta series
U2 - 10.1007/s12188-021-00231-5
DO - 10.1007/s12188-021-00231-5
M3 - Journal article
VL - 91
SP - 29
EP - 67
JO - Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg
JF - Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg
IS - 1
ER -