  Using a cluster extension of the dynamical mean-field theory, we show that
strongly correlated metals subject to Hund's physics exhibit significant
electronic structure modulations above magnetic transition temperatures. In
particular, in a ferromagnet having a large local moment due to Hund's coupling
(Hund's ferromagnet), the Fermi surface expands even above the Curie
temperature ($T_{\rm C}$) as if a spin polarization occurred. Behind this
phenomenon, effective ``Hund's physics'' works in momentum space, originating
from ferromagnetic fluctuations in the strong coupling regime. The resulting
significantly momentum-dependent (spatially nonlocal) electron correlations
induce an electronic structure reconstruction involving a Fermi-surface volume
change and a redistribution of the momentum-space occupation. Our finding will
give a deeper insight into the physics of Hund's ferromagnets above $T_{\rm
C}$.
