  We introduce coupled-cluster (CC) theory for the numerical study of the
normal state of two-component, dilute Fermi gases with attractive, short-range
interactions at zero temperature. We focus on CC theory with double excitations
(CCD) and discuss its close relationship with -- and improvement upon -- the
t-matrix approximation, i.e., the resummation of ladder diagrams via a
random-phase approximation. We further discuss its relationship with Chevy's
variational wavefunction ansatz for the Fermi polaron and argue that CCD is its
natural extension to nonzero minority species concentrations. Studying normal
state energetics for a range of interaction strengths below and above
unitarity, we find that CCD yields good agreement with fixed-node diffusion
Monte Carlo. We find that CCD does not converge for small polarizations and
large interaction strengths, which we speculatively attribute to the nascent
instability to a superfluid state.
