Euler Systems for ${\mathrm{GSp}}_4\times {\mathrm{GL}}_2$

Abstract

For a non-endoscopic cohomological cuspidal automorphic representation of ${\mathrm{GSp}}_4\times {\mathrm{GL}}_2$, assumed to be $p$-ordinary, we construct an Euler system for the Galois representation associated to it. Both the construction and the verification of tame norm relations are based on Novodvorsky's integral formula for the $L$-function of ${\mathrm{GSp}}_4\times {\mathrm{GL}}_2$.

54 pages. Simplified proof of local formula for tame norm relations. Added assumptions for tame norm relation to exclude boundary weights which do not go through the current proof. Other minor corrections