On triple product $L$-functions and the fiber bundle method
Jayce R. Getz, Miao Pam Gu, Chun-Hsien Hsu, Spencer Leslie
TL;DR
This work builds multivariable zeta integrals whose Euler products encode the triple product $L$-function together with auxiliary $L$-factors, situating the construction in a geometric framework of affine $oldsymbol{}$-bundles. A generalized Poisson summation conjecture is formulated for these spaces, and a fiber bundle strategy is proposed to reduce the global problem to tractable local and linear cases; a follow-up work GGHL2 is announced to complete the local analysis. The paper develops a robust function-theoretic and representation-theoretic apparatus—including Schwartz spaces, eigenmeasures, and line-bundle twists—along with local zeta integrals, including unramified computations that recover the expected $L$-factor structure. If the global Poisson summation conjecture holds (and the local hypotheses are resolved), this framework yields meromorphic continuation and functional equations for triple product $L$-functions, at least for $r_i>2$, marking a significant advance toward Langlands functoriality in higher rank. The fiber-bundle method provides a concrete roadmap for reducing global questions to local verifications on simpler geometric pieces, suggesting new avenues to attack long-standing conjectures via spectral and geometric techniques.
Abstract
We introduce multi-variable zeta integrals which unfold to Euler products representing the triple product $L$-function times a product of $L$-functions with known analytic properties. We then formulate a generalization of the Poisson summation conjecture and show how it implies the analytic properties of triple product $L$-functions. Finally, we propose a strategy, the fiber bundle method, to reduce this generalized conjecture to a simpler case of the Poisson summation conjecture along with certain local compatibility statements.
