Related papers: A dimensionally reduced expression for the QCD fer…
We evaluate the fermionic determinant for massless QED_2 at finite temperature, in the imaginary time formalism. By using a decoupling transformation of the fermionic fields, we show that the determinant factorizes into the usual,…
In this lecture we discuss various properties of the phase factor of the fermion determinant for QCD at nonzero chemical potential. Its effect on physical observables is elucidated by comparing the phase diagram of QCD and phase quenched…
The presence of a chemical potential completely changes the analytical structure of the QCD partition function. In particular, the eigenvalues of the Dirac operator are distributed over a finite area in the complex plane, whereas the zeros…
The concept of dimensional reduction in the high temperature regime is generalized to static Green's functions of composite operators that contain fermionic fields. The recognition of a natural kinematic region where the lowest Matsubara…
The expectation value of the complex phase factor of the fermion determinant is computed to leading order in the $p$-expansion of the chiral Lagrangian. The computation is valid for $\mu<m_\pi/2$ and determines the dependence of the sign…
QCD is expected to have a rich phase structure. It is empirically known to be difficult to access low temperature and nonzero chemical potential $\mu$ regions in lattice QCD simulations. We address this issue in a lattice QCD with the use…
We study the low temperature limit of lattice QCD by using a reduction formula for a fermion determinant. The reduction formula, which is useful in finite density lattice QCD simulations, contains a reduced matrix defined as the product of…
The current status of bounds on and limits of fermion determinants in two, three and four dimensions in QED and QCD is reviewed. A new lower bound on the two-dimensional QED determinant is derived. An outline of the demonstration of the…
We show that in the microscopic domain of QCD (also known as the $\epsilon$-domain) at nonzero chemical potential the average phase factor of the fermion determinant is nonzero for $\mu < m_\pi/2$ and is exponentially suppressed for larger…
We show how the prescription of taking the absolute value of the fermion determinant in the integration measure of QCD at finite density, forgetting its phase, reproduces the correct thermodynamical limit. This prescription, which applies…
Using an integration formula recently derived by Conrey, Farmer and Zirnbauer, we calculate the expectation value of the phase factor of the fermion determinant for the staggered lattice QCD action in one dimension. We show that the…
We evaluate exactly both the non-relativistic and relativistic fermion determinant in 2+1 dimensions in a constant background field at finite temperature. The effect of finite chemical potential is also considered. In both cases, the…
We study dynamical fermion effects in lattice QCD at finite temperature. The method adopted is basically the extrapolation from negative flavour numbers already tested at zero temperature and based on the simulation of local bosonic…
We study a longstanding problem in lattice QCD at low temperature and nonzero quark chemical potential on an onset of the quark number density at $\mu=m_\pi/2$. We introduce a physical parametrization of the eigenvalues in the reduction…
It is recommended that lattice QCD representations of the fermion determinant, including the discretization of the Dirac operator, be checked in the continuum limit against known QED determinant results. Recent work on the massive QED…
We report results of simulations of strong coupling, finite density QCD obtained within a MFA inspired approach where the fermion determinant in the integration measure is replaced by its absolute value. Contrary to the standard wisdom, we…
In this talk I will first give a short discussion of some lattice results for QCD at finite temperature. I will then describe in some detail the technique of dimensional reduction, which in principle is a powerful technique to obtain…
The general conditions for the Chern-Simons action to be induced as a nonuniversal contribution of fermionic determinant are formulated in the finite temperature lattice QCD. The dependence of the corresponding action coefficient on…
Finite temperature lattice QCD is probed by varying the temporal boundary conditions of the fermions. We develop the emerging physical behavior in a study of the quenched case and subsequently present first results for a fully dynamical…
In the large fermion mass limit of QCD at finite density the structure of the partition function greatly simplifies and can be studied analytically. We show that, contrary to general wisdom, the phase of the Dirac determinant is relevant…