show · mf.maass.mwf.dimension all knowls · up · search:

By the multiplicity of a Laplace eigenvalue we mean the dimension of the space \( \mathcal{M}(\Gamma,\chi,\lambda) \) of Maass waveforms on the group \( \Gamma \) and character \( \chi \) and the same Laplace eigenvalue \(\lambda\).

It is generally believed that these eigenspaces are one-dimensional unless there is a symmetry present. There are essentially three known cases where the dimension is greater than 1:

  1. If the eigenvalue corresponds to an oldspace in the sense of Atkin and Lehner.

  2. If the character \(\chi \) has quadratic characters as factors.

  3. If \(\Gamma=\Gamma_{0}(N)\) with $9|N$

The above three cases are proven and the generalization of 3. to other square factors greater than 9 is conjectured.

Knowl status:
  • Review status: reviewed
  • Last edited by Nathan Ryan on 2019-05-01 13:29:08
Referred to by:
History: (expand/hide all) Differences (show/hide)