  We investigate the properties of cold dense quark matter composed of two
colors and two flavors of light quarks. In particular, we perform the first
model calculation of the full phase diagram at nonzero baryon and isospin
density, thus matching the model-independent predictions of chiral perturbation
theory at low density to the conjectured phase structure at high density. We
confirm the presence of the Fulde-Ferrell (FF) phase in the phase diagram and
study its dependence on the tunable parameter in the Lagrangian that simulates
the effects of the quantum axial anomaly. As a byproduct, we clarify the
calculation of the thermodynamic potential in the presence of the FF pairing,
which was previously based on an ad hoc subtraction of an unphysical cutoff
artifact. Furthermore, we argue that close to the diquark (or pion)
Bose-Einstein condensation transition, the system behaves as a dilute Bose gas
so that our simple fermionic model in the mean-field approximation is not
quantitatively adequate. We suggest that including thermal fluctuations of the
order parameter for Bose-Einstein condensation is crucial for understanding
available lattice data.

High Energy Physics - Phenomenology;High Energy Physics - Lattice;Nuclear Theory