When cold, dense quarks in 1+1 and 3+1 dimensions are not a Fermi liquid

Understand

We analyze the behavior of quarks coupled to a $SU(N_c)$ gauge theory in 1+1 dimensions.

• In the limit of strong coupling, the model reduces to a Wess-Zumino-Novikov-Witten (WZNW) model.
• At nonzero density, excitations near the Fermi surface form a non-Fermi liquid.
• With $N_f$ flavors, the finite density of quarks reduce to a free $U(1)$ field, which governs fluctuations in baryon number, together with a WZNW $SU(N_f)$ nonlinear sigma model at level $N_c$, from the pion/kaon modes.