Dirichlet series and automorphic forms on unitary groups
HTML articles powered by AMS MathViewer
- by Tobias Orloff PDF
- Trans. Amer. Math. Soc. 290 (1985), 431-456 Request permission
Abstract:
In a special case our unitary group takes the form \[ G = \{ g \in {\text {GL}}(p + 2,{\mathbf {C}}){|^t}\bar gRg = R\} .\] Here \[ R = \left ( {\begin {array}{*{20}{c}} S & 0 & 0 \\ 0 & 0 & 1 \\ 0 & { - 1} & 0 \\ \end {array} } \right )\] is a skew-Hermitian matrix with entries in an imaginary quadratic number field $K$. We suppose that $- iR$ has signature $(p + 1,1)$. This group acts naturally on the symmetric domain \[ D = \left \{ {w \in {{\mathbf {C}}^p},z \in {\mathbf {C}}|\operatorname {Im} (z) > - {{\frac {1}{2}}^t}\bar wSw} \right \}.\] If $\Gamma = G \cap {\text {SL}}(p + 2,{\mathcal {O}_K})$ with ${\mathcal {O}_K}$ the ring of integers in $K$, then an automorphic form $f(w,z)$ with respect to $\Gamma$ has an expansion ${\Sigma _r}{g_r}(w) \cdot {e^{2\pi irz}}$. The functions ${g_r}(w)$ are theta functions. Given another automorphic form $g(w,z)$ with an expansion ${\Sigma _s}{h_s}(w) \cdot {e^{2\pi isz}}$ we define a Dirichlet series ${\Sigma _r}\langle {g_r},{h_r}\rangle {r^{ - s}}$ . Here $\langle {g_r},{h_r}\rangle$ is a certain positive definite inner product on the space of theta functions. The series is obtained as an integral of Rankin type: \[ {\int _{{P_\Gamma }\backslash D}}f\bar g\cdot {\left ( {\operatorname {Im} (z) + \frac {1} {2}{i^t}\bar wSw} \right )^s}dw\;d\bar w\;dz\;d\bar z\] with ${P_\Gamma } \subseteq \Gamma$ a subgroup of "translations". The series is analytically continued by studying the Eisenstein series arising when the above integral is transformed into an integral over $\Gamma \backslash D$. In the case $p = 1$ our results have an application to some recent work of Shintani, where the Euler product attached to an eigenfunction of the Hecke operators is obtained, up to some simple factors, as a series of the above type.References
- Armand Borel, Reduction theory for arithmetic groups, Algebraic Groups and Discontinuous Subgroups (Proc. Sympos. Pure Math., Boulder, Colo., 1965) Amer. Math. Soc., Providence, R.I., 1966, pp. 20–25. MR 0204533 Y. Flicker, $L$-packets and liftings for $U(3)$, preprint.
- Robert P. Langlands, On the functional equations satisfied by Eisenstein series, Lecture Notes in Mathematics, Vol. 544, Springer-Verlag, Berlin-New York, 1976. MR 0579181
- O. T. O’Meara, Introduction to quadratic forms, Die Grundlehren der mathematischen Wissenschaften, Band 117, Springer-Verlag, New York-Heidelberg, 1971. Second printing, corrected. MR 0347768
- Goro Shimura, Arithmetic of unitary groups, Ann. of Math. (2) 79 (1964), 369–409. MR 158882, DOI 10.2307/1970551
- Goro Shimura, On modular forms of half integral weight, Ann. of Math. (2) 97 (1973), 440–481. MR 332663, DOI 10.2307/1970831
- Goro Shimura, The arithmetic of automorphic forms with respect to a unitary group, Ann. of Math. (2) 107 (1978), no. 3, 569–605. MR 563087, DOI 10.2307/1971129
- Goro Shimura, The special values of the zeta functions associated with Hilbert modular forms, Duke Math. J. 45 (1978), no. 3, 637–679. MR 507462
- Goro Shimura, The arithmetic of certain zeta functions and automorphic forms on orthogonal groups, Ann. of Math. (2) 111 (1980), no. 2, 313–375. MR 569074, DOI 10.2307/1971202 T. Shintani, On automorphic forms on unitary groups of order $3$, preprint.
- Stephen S. Kudla, On certain Euler products for $\textrm {SU}(2,\,1)$, Compositio Math. 42 (1980/81), no. 3, 321–344. MR 607374 S. Gelbart and I. I. Piatetski-Shapiro, Automorphic forms and $L$-functions for the unitary group, preprint 1983.
- I. Piatetski-Shapiro, Tate theory for reductive groups and distinguished representations, Proceedings of the International Congress of Mathematicians (Helsinki, 1978) Acad. Sci. Fennica, Helsinki, 1980, pp. 585–590. MR 562659
Additional Information
- © Copyright 1985 American Mathematical Society
- Journal: Trans. Amer. Math. Soc. 290 (1985), 431-456
- MSC: Primary 11F55
- DOI: https://doi.org/10.1090/S0002-9947-1985-0792806-0
- MathSciNet review: 792806