Local-global compatibility and the exceptional zero conjecture for GL(3)
Daniel Barrera Salazar, Andrew Graham, Chris Williams
TL;DR
The paper studies exceptional zero phenomena for p-adic L-functions attached to regular algebraic cuspidal automorphic representations of GL3 that are p-ordinary with Steinberg at p and no self-duality assumption. It develops an automorphic L-invariant framework via p-arithmetic cohomology and extensions of generalized Steinberg representations, proving an abstract exceptional zero formula and an explicit automorphic derivative formula for L_p(π,s). Concurrently, it establishes local-global compatibility at p for Galois representations arising from GL3 eigenvarieties, and proves equality of automorphic and Fontaine–Mazur L-invariants in broad settings, leveraging trianguline deformation theory. In the symmetric-square (essentially self-dual) case, it connects to Rosso’s results and extends to non-self-dual cases through a trianguline/fundamental-lemma–type approach, providing new instances of the Greenberg–Benois exceptional zero conjectures for GL3 without self-duality. The work unifies automorphic constructions with p-adic Hodge-theoretic invariants, yielding precise derivative formulas for L_p^{(c)} at critical points and establishing a path to p-part of the Bloch–Kato conjecture in higher rank settings.
Abstract
We prove exceptional zero conjectures for $p$-ordinary regular algebraic cuspidal automorphic representations of $\mathrm{GL}_3(\mathbb{A})$ which are Steinberg at $p$. We make no self-duality assumptions. The paper has two parts. In Part 1, we use $p$-arithmetic cohomology to unconditionally prove an automorphic exceptional zero conjecture in this setting, using Gehrmann's automorphic $\mathcal{L}$-invariant. In Part 2 we prove, under mild assumptions that are expected to always hold, the equality of automorphic and Fontaine--Mazur $\mathcal{L}$-invariants, and thus deduce cases of the full Greenberg--Benois exceptional zero conjecture. As one of the key ingredients for this, we establish local-global compatibility at $\ell = p$ for Galois representations attached to $p$-ordinary torsion classes for $\mathrm{GL}_n$, confirming a conjecture of Hansen in this setting. We prove this for all $n$ following the strategy in the "10-author paper", and use the $n=3$ case to deduce the desired equality of $\mathcal{L}$-invariants.
