Related papers: Effective Action and Conformal Phase Transition in…
In this paper we calculate the divergent part of the one loop effective action for QED on noncommutative space using the background field method. The effective action is obtained up to the second order in the noncommutative parameter theta…
The QCD phase diagram at imaginary chemical potential exhibits a rich structure and studying it can constrain the phase diagram at real values of the chemical potential. Moreover, at imaginary chemical potential standard numerical…
Strongly coupled QED is a model whose physics is dominated by short-ranged effects. In order to assess which features of numerical simulations of the chiral phase transition are universal and which are not, we have formulated a quenched…
We calculated QED corrections to the $E1$ transition amplitudes in Ne-like iron and nickel. For the $2p \to 3d$ transitions the dominant effect came from the many-electron mixing, or electronic correlations. For the $2p \to 3s$ transitions…
We propose a method to probe the nature of phase transitions in lattice QCD at finite temperature and density, which is based on the investigation of an effective potential as a function of the average plaquette. We analyze data obtained in…
We study the nature of the finite temperature phase transition for three-flavor QCD. In particular we investigate the location of the critical endpoint along the three flavor symmetric line in the light quark mass region of the Columbia…
The chiral phase transition at finite temperature T and/or chemical potential $\mu$ is studied using the QCD-like theory with a variational approach. The ``QCD-like theory'' means the improved ladder approximation with an infrared cutoff in…
While the composite fermion picture is so effective as to describe the excitation spectra including the spin wave for Laughlin's quantum liquid, ``how heavy and how strongly-interacting" remains a formidable question for the composite…
The effective potential of scalar QED is computed analytically up to two loops in the Landau gauge. The result is given in 4-epsilon dimensions using minimal subtraction and epsilon-expansions. In three dimensions, our calculation is…
The effective action for the multi-Regge asymptotics is considered as a first step in calculating the unitarity correction to the perturbative pomeron. It can be derived from the original QCD action by intgrating out certain modes of the…
The QED effective Lagrangian in the presence of an arbitrary constant electromagnetic background field at finite temperature is derived in the imaginary-time formalism to one-loop order. The boundary conditions in imaginary time reduce the…
The quark determinant in the presence of a background gluon field is calculated in a large quark mass approach within a derivative expansion by considering quark sources. The resulting low-energy QCD Effective Field Theory (EFT) is valid…
An interesting class of background field configurations in QED are the O(2)xO(3) symmetric fields. Those backgrounds have some instanton-like properties and yield a one-loop effective action that is highly nontrivial but amenable to…
We apply the resolvent technique to the computation of the QED effective action in time dependent electric field backgrounds. The effective action has both real and imaginary parts, and the imaginary part is related to the pair production…
We study a series of the Wess-Zumino actions obtained by repeatedly integrating conformal anomalies with respect to the conformal-factor field that appear at higher loops. We show that they arise as physical quantities required to make…
By comparison of the quenched and full formulations of compact QED with Wilson fermions we single out the effects of dynamical fermions on the `chiral transition line' within the confinement phase. It is shown that this line cannot…
We have proven the general relations between the gap equations obeyed by dynamical fermion mass and corresponding effective potentials at finite temperature and chemical potential in D dimensional four-fermion interaction models. This gives…
Flow equations for an O(N)-symmetric effective potential are discussed and solved for the finite temperature case. The model is investigated at the critical point and critical exponents for various N are calculated.
We study a low-energy effective field theory (EFT) describing the NN system in which all exchanged particles are integrated out. We show that fitting the residue of the 3S1 amplitude at the deuteron pole, rather than the 3S1 effective…
We study the analytical structure of the effective action for spin- and mass-imbalanced Fermi mixtures at the onset of the superfluid state. Of our particular focus is the possibility of suppressing the tricritical temperature to zero, so…