In mathematics , the Shimizu L -function , introduced by Hideo Shimizu (1963 ), is a Dirichlet series associated to a totally real algebraic number field .
Michael Francis Atiyah , H. Donnelly, and I. M. Singer (1983 )
defined the signature defect of the boundary of a manifold as the eta invariant , the value as s =0 of their eta function, and used this to show that Hirzebruch's signature defect of a cusp of a Hilbert modular surface can be expressed in terms of the value at s =0 or 1 of a Shimizu L-function.
Suppose that K is a totally real algebraic number field, M is a lattice in the field, and V is a subgroup of maximal rank of the group of totally positive units preserving the lattice. The Shimizu L-series is given by
L
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M
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{
M
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/
V
sign
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s
{\displaystyle L(M,V,s)=\sum _{\mu \in \{M-0\}/V}{\frac {\operatorname {sign} N(\mu )}{|N(\mu )|^{s}}}}
Atiyah, Michael Francis ; Donnelly, H.; Singer, I. M. (1982), "Geometry and analysis of Shimizu L-functions", Proceedings of the National Academy of Sciences of the United States of America , 79 (18): 5751, Bibcode :1982PNAS...79.5751A , doi :10.1073/pnas.79.18.5751 , ISSN 0027-8424 , JSTOR 12685 , MR 0674920 , PMC 346984 , PMID 16593231
Atiyah, Michael Francis ; Donnelly, H.; Singer, I. M. (1983), "Eta invariants, signature defects of cusps, and values of L-functions", Annals of Mathematics , Second Series, 118 (1): 131– 177, doi :10.2307/2006957 , ISSN 0003-486X , JSTOR 2006957 , MR 0707164
Shimizu, Hideo (1963), "On discontinuous groups operating on the product of the upper half planes", Annals of Mathematics , Second Series, 77 (1): 33– 71, doi :10.2307/1970201 , ISSN 0003-486X , JSTOR 1970201 , MR 0145106