In the past few years a growing consensus has been building around the idea that a spatially inhomogeneous chiral condensate may form in dense quark matter. In this talk, I will give a brief historical overview and review some recent developments on the characterization of such crystalline condensates using effective models for describing of QCD at finite density.
I will summarize the structure and scope of the so-called melonic large N expansion, which typically governs the large N behaviour of theories involving higher rank tensors. Compared to vector and matrix theories, What distinguishes it from the large N expansions of vector or matrix theories is that it is dominated by a non-trivial family of Feynman diagrams -- the melon diagrams -- which...
