  The electronic band structure of bulk ferromagnetic iron is explored by
angle-resolved photoemission for electron correlation effects. Fermi surface
cross-sections as well as band maps are contrasted with density functional
calculations. The Fermi vectors and band parameters obtained from photoemission
and their prediction from band theory are analyzed in detail. Generally good
agreement is found for the Fermi surface. A bandwidth reduction for shallow
bands of ~ 30 % is observed. Additional strong quasiparticle renormalization
effects are found near the Fermi level, leading to a considerable mass
enhancement. The role of electronic correlation effects and the electronic
coupling to magnetic excitations is discussed in view of the experimental
results.
