Nonvanishing of HeckeL-Functions Associated to Cusp Forms inside the Critical Strip
Nonvanishing of HeckeL-Functions Associated to Cusp Forms inside the Critical Strip
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DOI:
10.1006/jnth.1997.2178
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发表时间:
1997-12
影响因子:
0.7
通讯作者:
W. Kohnen
中科院分区:
文献类型:
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作者:
W. Kohnen
Let f be a non-zero cuspidal Hecke eigenform of integral weight k on the full modular group SL2 (Z) and denote by L*(f, s)(s# C) the associated Hecke L-function completed with its natural 1-factor. As is well-known, zeroes of L*(f, s) can occur only inside the critical strip (k&1) Ā2< Re (s)<(k+ 1) Ā2, and according to the generalized Riemann hypothesis they should all lie on the line Re (s)= kĀ2. While at present a proof of the Riemann hypothesis seems to be out of reach, it turns out to be rather easy to show nonvanishing results for L-functions on the average. In fact, in the present paper we shall prove that, given a real number t0 and a positive real number=, for all k large enough the sum of the functions L*(f, s) with f running over a basis of (properly normalized) Hecke eigenforms of weight k does not vanish on the line segments Im (s)= t0,(k&1) Ā2< Re (s)<(kĀ2) &=,(kĀ2)+=< Re (s)<(k+ 1) Ā2. For the proof we consider the cusp forms dual wrt the Petersson scalar product of the values L*(f, s); these functions are generalizations of the period functions studied in [3]. We compute their Fourier expansion and estimate the first Fourier coefficient in an appropriate way. The result then will turn out.