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Related papers: Effective actions at finite temperature

200 papers

In this work we consider a fermionic quantum gas within a Lorentz-Violating background at finite temperature. We derive the effective action within Path Integral formalism considering the interaction of external electromagnetic field and…

High Energy Physics - Theory · Physics 2024-01-29 Rafael L. J. Costa , Rodrigo F. Sobreiro

We study numerically the finite temperature and frequency mobility of a particle coupled by a local interaction to a system of spinless fermions in one dimension. We find that when the model is integrable (particle mass equal to the mass of…

Condensed Matter · Physics 2009-10-28 H. Castella , X. Zotos

We follow the dynamics of an ensemble of interacting self-propelled motorized particles in contact with an equilibrated thermal bath. We find that the fluctuation-dissipation relation allows for the definition of an effective temperature…

Soft Condensed Matter · Physics 2015-05-13 Davide Loi , Stefano Mossa , Leticia F. Cugliandolo

This is the first paper in a series of three dealing with HS theories in flat spacetime. It is divided in three parts. The first part is an elaboration on the method of effective action, initiated in a previous paper. We study the…

High Energy Physics - Theory · Physics 2019-05-01 L. Bonora , M. Cvitan , P. Dominis Prester , S. Giaccari , M. Stemberga

We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the…

High Energy Physics - Theory · Physics 2009-10-30 Daniel Cangemi , Gerald Dunne

We revisit the Hawking radiation by comparing the effective actions in the in-out formalism, and advance an interpretation of the vacuum polarization and the Hawking radiation. The equivalence exists between the spinor QED effective action…

High Energy Physics - Theory · Physics 2012-04-19 Sang Pyo Kim

Using the mixed space representation, we extend our earlier analysis to the case of Dirac and gauge fields and show that in the absence of a chemical potential, the finite temperature Feynman diagrams can be related to the corresponding…

High Energy Physics - Theory · Physics 2008-11-26 Fernando T. Brandt , Ashok Das , Olivier Espinosa , Josif Frenkel , Silvana Perez

The effective action for local composite operators in $QED_3$ is considered. The effective potential is calculated in leading order in $1/N_f$ ($N_f$ is the number of fermion flavors) and used to describe the features of the phase…

High Energy Physics - Theory · Physics 2009-10-31 V. P. Gusynin , V. A. Miransky , A. V. Shpagin

A recent description of an exact map for the equilibrium structure and thermodynamics of a quantum system onto a corresponding classical system is summarized. Approximate implementations are constructed by pinning exact limits (ideal gas,…

Statistical Mechanics · Physics 2015-04-14 Jeffrey Wrighton , James Dufty , Sandipan Dutta

I consider the calculation of the two and three-point functions for QED at finite temperature in the presence of a background plasma velocity. The final expressions are consistent with Lorentz invariance, gauge invariance and current…

High Energy Physics - Phenomenology · Physics 2010-12-17 D. Metaxas

We introduce effective form factors for one-dimensional lattice fermions with arbitrary phase shifts. We study tau functions defined as series of these form factors. On the one hand we perform the exact summation and present tau functions…

Statistical Mechanics · Physics 2021-03-24 O. Gamayun , N. Iorgov , Yu. Zhuravlev

It is known that the one-loop effective action of ${QED}_2$ is a quadratic in the field strength when the fermion mass is zero: all potential higher order contributions beyond second order vanish. For nonzero fermion mass it is shown that…

High Energy Physics - Theory · Physics 2014-11-18 M. P. Fry

Thermal properties of quantum fields at finite temperature are crucial to understanding strongly interacting matter and recent development in quantum computing has provided an alternative and promising avenue of study. In this work, we…

High Energy Physics - Phenomenology · Physics 2024-07-23 Wenyang Qian , Bin Wu

If violation of Lorentz and CPT symmetry is introduced into the fermion sector of conventional quantum electrodynamics, then the Chern-Simons term is radiatively induced with finite nonzero coefficient, as well as the Maxwell term is with…

High Energy Physics - Theory · Physics 2014-11-18 Yu. A. Sitenko

For the same quantum field theory distinct effective actions can be obtained by coupling sources to different choices of field variables. This is the same as considering effective actions for theories related by a change of variables and…

High Energy Physics - Theory · Physics 2025-08-25 Kevin Falls

In this work we analyze how effects of finite size may modify the thermodynamics of a system of strongly interacting fermions that we model using an effective field theory with four-point interactions at finite temperature and density and…

High Energy Physics - Theory · Physics 2015-06-11 Antonino Flachi

Finite temperature density functional theory provides, in principle, an exact description of the thermodynamical equilibrium of many-electron systems. In practical applications, however, the functionals must be approximated. Efficient and…

Statistical Mechanics · Physics 2015-05-19 S. Pittalis , C. R. Proetto , A. Floris , A. Sanna , C. Bersier , K. Burke , E. K. U. Gross

We present a study of the effective action approach to incorporate higher-order effects in e^+e^- -> n fermions. In its minimal version, the effective action approach is found to exhibit problems with unitarity and high-energy behaviour. We…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. Beenakker , A. P. Chapovsky , A. Kanaki , C. G. Papadopoulos , R. Pittau

The effective action for hard thermal loops in QCD is related to a gauged WZNW theory. Some of the technical issues of this approach are clarified and the Hamiltonian formulation is presented. The two-point correlation function for the…

High Energy Physics - Theory · Physics 2009-10-28 V. P. Nair

We develop a description of fermionic superfluids in terms of an effective field theory for the pairing order parameter. Our effective field theory improves on the existing Ginzburg - Landau theory for superfluid Fermi gases in that it is…

Quantum Gases · Physics 2015-06-05 S. N. Klimin , J. Tempere , G. Lombardi , J. T. Devreese