Related papers: Simulating Dense Matter
The order of the phase transition in finite-temperature QCD with two degenerate light quarks is still an open problem and corresponds to the last question mark in the zero-density phase diagram of QCD. We argue that establishing the nature…
A disorder parameter detecting dual superconductivty of the vacuum is used as a probe to characterize the confining properties of the phase diagram of two color QCD at finite temperature and density. We obtain evidence for the disappearing…
We propose a practical way of circumventing the sign problem in lattice QCD simulations with a theta-vacuum term. This method is the reweighting method for the QCD Lagrangian after the chiral transformation. In the Lagrangian, the P-odd…
We point out that SO(2N_{c}) gauge theory with N_{f} fundamental Dirac fermions does not have a sign problem at finite baryon number chemical potential \mu_{B}. One can thus use lattice Monte Carlo simulations to study this theory at finite…
QCD at fixed baryon number can be formulated in terms of transfer matrices explicitly defined in the canonical sectors. In the heavy-dense limit, the fermionic contributions to the canonical partition functions in terms of Polyakov loops…
We investigate the Euclidean path integral formulation of QCD at finite baryon density and temperature. We show that the partition function Z can be written as a difference between two sums Z+ and Z-, each of which defines a partition…
We propose a method to determine the total magnetic susceptibility of strongly interacting matter by lattice QCD simulations, and present first numerical results for the theory with two light flavors, which suggest a weak magnetic activity…
Recently, cluster methods have been used to solve a variety of sign problems including those that arise in the presence of fermions. In all cases an analytic partial re-summation over a class of configurations in the path integral was…
The effect of the complex phase of the fermion determinant is a key question related to the sign problem in finite-density QCD. Recently it has been shown that ignoring the complex phase -- the phase quenching -- does not change physics in…
In this talk we show how the sign problem, occurring in dynamical simulations of random matrices at nonzero chemical potential, can be avoided by judiciously combining matrices into subsets. One can prove that these subsets have real and…
A quasi-particle model is presented which describes QCD lattice results for the 0, 2 and 4 quark-flavor equation of state. The results are mapped to finite baryo-chemical potentials. As an application of the model we make a prediction of…
Monte Carlo calculations in the framework of lattice field theory provide non-perturbative access to the equilibrium physics of quantum fields. When applied to certain fermionic systems, or to the calculation of out-of-equilibrium physics,…
Using combined strong coupling and hopping parameter expansions, we derive an effective three-dimensional theory from thermal lattice QCD with heavy Wilson quarks. The theory depends on traced Polyakov loops only and correctly reflects the…
For a long time, strong coupling expansions have not been applied systematically in lattice QCD thermodynamics, in view of the succes of numerical Monte Carlo studies. The persistent sign problem at finite baryo-chemical potential, however,…
We propose a "matter-antimatter coexistence method" for finite-density lattice QCD, aiming at a possible solution of the sign problem. In this method, we consider matter and anti-matter systems on two parallel ${\bf R}^4$-sheets in…
Although numerical simulation in lattice field theory is one of the most effective tools to study non-perturbative properties of field theories, it faces serious obstacles coming from the sign problem in some theories such as finite density…
Developments in QCD at finite density are reviewed. I begin by discussing some new algorithms which have been applied to other theories with sign problems. Then I discuss the method of analytic continuation in QCD using a series expansion…
We review recent progress in Monte Carlo simulations of dense two-color QCD (QC$_2$D), focusing on the phase diagram, the equation of state, and the sound velocity in the low-temperature regime. In three-color QCD at finite density,…
The thermal restoration of chiral symmetry in QCD is known to proceed by an analytic crossover, which is widely expected to turn into a phase transition with a critical endpoint as the baryon density is increased. In the absence of a…
Lattice simulations of non-zero density QCD introduce the so-called sign problem (complex or negative probabilities), which invalidates importance sampling methods. To circumvent this, we use the Complex Langevin Equation (CLE), to measure…