  We present fully ab initio simulations of attosecond streaking for ionization
of helium accompanied by shake-up of the second electron. This process
represents a prototypical case for strongly correlated electron dynamics on the
attosecond timescale. We show that streaking spectroscopy can provide detailed
information on the Eisenbud-Wigner-Smith time delay as well as on the infrared
field dressing of both bound and continuum states. We find a novel contribution
to the streaking delay that stems from the interplay of electron-electron and
infrared-field interactions in the exit channel. We quantify all the
contributions with attosecond precision and provide a benchmark for future
experiments.
