DETERMINING MULTIPLICITIES OF HALF-INTEGRAL WEIGHT NEWFORMS
DETERMINING MULTIPLICITIES OF HALF-INTEGRAL WEIGHT NEWFORMS
复制标题
确定半积分重新形式的重数
DOI:
10.2140/pjm.1995.167.345
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发表时间:
1995
影响因子:
0.6
通讯作者:
L. Walling
中科院分区:
文献类型:
--
作者:
T. Shemanske;L. Walling
We decompose the space of newforms of half-integral weight into a direct sum of spaces of newforms of integral weight which occur with multiplicity one or two. This not only demonstrates in a precise way the failure of a multiplicity-one result to hold for half-integral weight newforms, but moreover indicates which spaces occur with a given multiplicity. The spaces occuring with multiplicity two are shown to be in one-to-one correspondence with a collection of Kohnen subspaces. As a consequence, it is shown that under the Shimura correspondence, the level a newform of half-integral weight is not determined by the level of the integral weight newform to which it corresponds. Since a knowledge of the Hecke eigenvalues is insuffi-cient to charectesize half-integral weight newforms up to a scalar, we develop sufficient conditions on the squarefree coefficients, augmenting the information on the eigenvalues, which allow such a characterization. In the last section, these later results are carried over to the Hubert modular setting.