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Spherical Shalika models on PGU2,2 and the theta correspondence for (PGSp4, PGU2,2)

  • Antonio Cauchi ORCID logo EMAIL logo and Armando Gutierrez Terradillos
Published/Copyright: March 28, 2025
Forum Mathematicum
From the journal Forum Mathematicum

Abstract

We study Shalika models for generic unramified representations of PGU 2 , 2 over non-archimedean local fields of characteristic zero. We show that they are unique up to constant by means of the theta correspondence for ( PGSp 4 , PGU 2 , 2 ) . We then prove a Casselman–Shalika formula which relates the values of spherical Shalika functionals on PGU 2 , 2 to the values of finite-dimensional complex representations of the dual group of PGSp 4 .

MSC 2020: 11F27; 11F66; 11F70

Communicated by Freydoon Shahidi


Award Identifier / Grant number: RGPIN-2018-04392

Award Identifier / Grant number: 682152

Funding statement: Antonio Cauchi’s research in this publication was conducted with the financial support of the NSERC grant RGPIN-2018-04392 and Concordia Horizon postdoc fellowship n.8009, of the JSPS Postdoctoral Fellowship for Research in Japan, and of Taighde Éireann – Research Ireland under Grant number IRCLA/2023/849 (HighCritical). Armando Gutierrez Terradillos was supported by the Morningside Center of Mathematics (CAS). Both authors were also supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 682152).

Acknowledgements

The project started when the two authors were both working at the Universitat Politecnica de Catalunya; we thus kindly thank Victor Rotger for his support. We are indebted to Wee Teck Gan, who explained to us how to prove uniqueness of Shalika models by means of the local theta correspondence. The first named author would also like to thank Patrick Allen, Mathilde Gerbelli-Gauthier, Aaron Pollack, Martí Roset Julià, and Giovanni Rosso for discussions related to this project. Finally, we would like to thank the anonymous referee for the valuable corrections and comments that helped us to considerably improve this article.

References

[1] J. D. Adler and D. Prasad, On certain multiplicity one theorems, Israel J. Math. 153 (2006), 221–245. Search in Google Scholar

[2] D. Blasius and J. D. Rogawski, Zeta functions of Shimura varieties, Motives (Seattle 1991), Proc. Sympos. Pure Math. 55, American Mathematical Society, Providence (1994), 525–571. Search in Google Scholar

[3] D. Bump, The Rankin–Selberg method: An introduction and survey, Automorphic Representations, L-Functions and Applications: Progress and Prospects, Ohio State Univ. Math. Res. Inst. Publ. 11, de Gruyter, Berlin (2005), 41–73. Search in Google Scholar

[4] D. Bump, S. Friedberg and D. Ginzburg, Whittaker-orthogonal models, functoriality, and the Rankin–Selberg method, Invent. Math. 109 (1992), no. 1, 55–96. Search in Google Scholar

[5] P. Cartier, Representations of p-adic groups: A survey, Automorphic Forms, Representations and L-Functions (Corvallis 1977), Proc. Sympos. Pure Math. 33, American Mathematical Society, Providence (1979), 111–155. Search in Google Scholar

[6] W. Casselman, The unramified principal series of p-adic groups. I. The spherical function, Compos. Math. 40 (1980), no. 3, 387–406. Search in Google Scholar

[7] W. Casselman and J. Shalika, The unramified principal series of p-adic groups. II. The Whittaker function, Compos. Math. 41 (1980), no. 2, 207–231. Search in Google Scholar

[8] A. Cauchi and A. Gutierrez Terradillos, A two variable Rankin–Selberg integral for GU ( 2 , 2 ) and the degree 5 L-function of GSp 4 , Math. Z. 308 (2024), no. 2, Paper No. 29. Search in Google Scholar

[9] W. Fulton and J. Harris, Representation Theory, Grad. Texts in Math. 129, Springer, New York, 2013. Search in Google Scholar

[10] M. Furusawa and K. Morimoto, Shalika periods on GU ( 2 , 2 ) , Proc. Amer. Math. Soc. 141 (2013), no. 12, 4125–4137. Search in Google Scholar

[11] W. T. Gan and S. Takeda, The local Langlands conjecture for Sp(4), Int. Math. Res. Not. IMRN 2010 (2010), no. 15, 2987–3038. Search in Google Scholar

[12] S. Gelbart, I. Piatetski-Shapiro and S. Rallis, Explicit Constructions of Automorphic L-Functions, Lecture Notes in Math. 1254, Springer, Berlin, 1987. Search in Google Scholar

[13] S. S. Gelbart and A. W. Knapp, L-indistinguishability and R groups for the special linear group, Adv. Math. 43 (1982), no. 2, 101–121. Search in Google Scholar

[14] Y. Hironaka, Spherical functions and local densities on Hermitian forms, J. Math. Soc. Japan 51 (1999), no. 3, 553–581. Search in Google Scholar

[15] H. Jacquet and S. Rallis, Uniqueness of linear periods, Compos. Math. 102 (1996), no. 1, 65–123. Search in Google Scholar

[16] H. Jacquet and J. Shalika, Exterior square L-functions, Automorphic Forms, Shimura Varieties, and L-Functions, Vol. II (Ann Arbor 1988), Perspect. Math. 11, Academic Press, Boston (1990), 143–226. Search in Google Scholar

[17] J.-S. Li, Some results on the unramified principal series of p-adic groups, Math. Ann. 292 (1992), no. 4, 747–761. Search in Google Scholar

[18] C. Mœglin, M.-F. Vignéras and J.-L. Waldspurger, Correspondances de Howe sur un corps p-adique, Lecture Notes in Math. 1291, Springer, Berlin, 1987. Search in Google Scholar

[19] K. Morimoto, On the theta correspondence for ( GSp ( 4 ) , GSO ( 4 , 2 ) ) and Shalika periods, Represent. Theory 18 (2014), 28–87. Search in Google Scholar

[20] D. Prasad, Trilinear forms for representations of GL ( 2 ) and local ε-factors, Compos. Math. 75 (1990), no. 1, 1–46. Search in Google Scholar

[21] B. Roberts and R. Schmidt, Local Newforms for GSp(4), Lecture Notes in Math. 1918, Springer, Berlin, 2007. Search in Google Scholar

[22] Y. Sakellaridis, A Casselman–Shalika formula for the Shalika model of GL n , Canad. J. Math. 58 (2006), no. 5, 1095–1120. Search in Google Scholar

[23] F. Shahidi, On certain L-functions, Amer. J. Math. 103 (1981), no. 2, 297–355. Search in Google Scholar

Received: 2024-03-18
Revised: 2025-02-07
Published Online: 2025-03-28

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