Derived Hecke algebra and automorphic L-invariants

Abstract

Let $\pi$ be a cohomological automorphic representation of $PGL(2)$ over a number field of arbitrary signature and assume that the local component of $\pi$ at a prime $\mathfrak{p}$ is the Steinberg representation. In this situation one can define an automorphic $\mathcal{L}$-invariant for each cohomological degree in which the system of Hecke eigenvalues associated to $\pi$ occurs. We show that these $\mathcal{L}$-invariants are (essentially) the same if the $\pi$-isotypic component of the cohomology is generated by the minimal degree cohomology as a module over Venkatesh's derived Hecke algebra.

16 pages, details added, to appear in Trans. Amer. Math. Soc