Large-N spacetime reduction and the sign and silver-blaze problems of dense QCD

Abstract

We study the spacetime-reduced (Eguchi-Kawai) version of large-N QCD with nonzero chemical potential. We explore a method to suppress the sign fluctuations of the Dirac determinant in the hadronic phase; the method employs a re-summation of gauge configurations that are related to each other by center transformations. We numerically test this method in two dimensions, and find that it successfully solves the silver-blaze problem. We analyze the system further, and measure its free energy F, the average phase theta of its Dirac determinant, and its chiral condensate <psi-bar-psi>. We show that F and <psi-bar-psi> are independent of mu in the hadronic phase but that, as chiral perturbation theory predicts, the quenched chiral condensate drops from its mu=0 value when mu~(pion mass)/2. Finally, we find that the distribution of theta qualitatively agrees with further, more recent, predictions from chiral perturbation theory.

43 pages, 17 figures

References in corpus (5)

• Can stochastic quantization evade the sign problem? -- the relativistic Bose gas at finite chemical potential
• Volume independence in large Nc QCD-like gauge theories
• The quark mass dependence of the pion mass at infinite N
• The vector meson mass in the large N limit of QCD
• Phase Fluctuation of Fermion Determinant in Lattice QCD at Finite Density

Cited by in corpus (5)

• On the convergence of complex Langevin dynamics: the three-dimensional XY model at finite chemical potential
• Subset method for one-dimensional QCD
• A subset solution to the sign problem in random matrix simulations
• QCD With A Chemical Potential, Topology, And The 't Hooft 1/N Expansion
• Silver Blaze Puzzle in 1/Nc Expansions of Cold and Dense QCD Matter