Maass forms

수학노트
둘러보기로 가기 검색하러 가기

introduction

  • Hyperbolic distribution problems and half-integral weight Maass forms
  • Automorphic forms correspond to representations that occur in \(L_2(\Gamma\backslash G)\).
  • In the case when \(G\) is \(SL(2,\mathbb{R})\)
    • holomorphic modular forms correspond to (highest weight vectors of) discrete series representations of \(G\)
    • Maass wave forms correspond to (spherical vectors of) continuous series representations of G.


definition

  • A Maass (wave) form = continuous complex-valued function f of τ = x + iy in the upper half plane satisfying the following conditions:
    • f is invariant under the action of the group SL2(Z) on the upper half plane.
    • f is an eigenvector of the Laplacian operator \(\Delta=-y^2\left(\frac{\partial^2}{\partial x^2} + \frac{\partial^2}{\partial y^2}\right)\)
    • f is of at most polynomial growth at cusps of SL2(Z).


two types of Maass forms

  • square integrable Maass forms ~ discrete spectrum
  • Eisenstein series ~ continuous spectrum


fourier expansion

  • \(f(z+1)=f(z)\) and \(\Delta f=\lambda f\) where \(\lambda = s(1-s)\) and \(\Re s \geq 1/2\) imply

\[ f(x+iy)=\sum_{n\in \mathbb{Z}}a_n \sqrt{y}K_{s-1/2}(2\pi |n| y) e^{2\pi i n x} \] where \(K_{\nu}\) is the modified Bessel function of the second kind

  • under the assumption that \(f(x+iy)=f(-x+iy)\), we get

\[ f(x+iy)=\sum_{n=1}^{\infty}a_n \sqrt{y}K_{s-1/2}(2\pi n y) \cos (2\pi i n x) \]


examples

Eisenstein series


Maass-Poincare series

  • Hejhal
  • real analytic eigenfunction of the Laplacian with known singularities at \(i\infty\)


Kloosterman sum


related items


books

  • Henryk Iwaniek, Emmanuel Kowalski (2004). Analytic number theory
  • Lectures on modular functions of one complex variable (Tata Institute of Fundamental Research. Lectures on mathematics and physics. Mathematics, 29)
    • Hans Maass, (pdf)


computational resource

encyclopedia


question and answers(Math Overflow)


expositions


articles

  • Farrell Brumley, Simon Marshall, Lower bounds for Maass forms on semisimple groups, arXiv:1604.02019 [math.NT], April 07 2016, http://arxiv.org/abs/1604.02019
  • Strömberg, Fredrik. “Computation of Maass Waveforms with Nontrivial Multiplier Systems.” Mathematics of Computation 77, no. 264 (2008): 2375–2416. doi:10.1090/S0025-5718-08-02129-7.
  • Booker, Andrew R., Andreas Strömbergsson, and Akshay Venkatesh. “Effective Computation of Maass Cusp Forms.” International Mathematics Research Notices 2006 (January 1, 2006): 71281. doi:10.1155/IMRN/2006/71281.

메타데이터

위키데이터

Spacy 패턴 목록

  • [{'LOWER': 'maass'}, {'LOWER': 'wave'}, {'LEMMA': 'form'}]
  • [{'LOWER': 'maass'}, {'LOWER': 'cusp'}, {'LEMMA': 'form'}]
  • [{'LOWER': 'maass'}, {'LEMMA': 'form'}]