## An Euler system for genus 2 Siegel modular forms

Abstract: Euler systems are compatible families of cohomology classes for a global Galois represenation, which plan an important role in studying Selmer groups. I will outline the construction of a new Euler system, for the Galois representation associated to a cohomological cuspidal automorphic representation on the symplectic group GSp(4). This is joint work with Chris Skinner and Sarah Zerbes.