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On the Free Energy of Noncommutative Quantum Electrodynamics at High Temperature

F. T. Brandt·J. Frenkel·C. M. Muramoto
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Abstract

We compute higher order contributions to the free energy of noncommutative quantum electrodynamics at a nonzero temperature $T$. Our calculation includes up to three-loop contributions (fourth order in the coupling constant $e$). In the high temperature limit we sum all the {\it ring diagrams} and obtain a result which has a peculiar dependence on the coupling constant. For large values of $eθT^2$ ($θ$ is the magnitude of the noncommutative parameters) this non-perturbative contribution exhibits a non-analytic behavior proportional to $e^3$. We show that above a certain critical temperature, there occurs a thermodynamic instability which may indicate a phase transition.

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F. T. Brandt, J. Frenkel, C. M. Muramoto. 2006-09-28. On the Free Energy of Noncommutative Quantum Electrodynamics at High Temperature. https://doi.org/10.1016/j.nuclphysb.2006.07.011

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