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A Generalization of Level-Raising Congruences for Algebraic Modular Forms

Claus Mazanti Sorensen
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Abstract

In this paper we prove a general theorem about congruences between automorphic forms on a reductive group G which is compact at infinity modulo the center. If the rank is one, this essentially reduces to Ribet's level-raising theorem. We then specialize to the higher rank case where G is an inner form of GSp(4). Here we get congruences with automorphic forms having a generic local component. In particular, a Saito-Kurokawa form is congruent to a form which is not of Saito-Kurokawa type. We get similar results for U(3) at split primes.

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Claus Mazanti Sorensen. 2005-04-15. A Generalization of Level-Raising Congruences for Algebraic Modular Forms. https://arxiv.org/abs/math/0504332

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