High-temperature plasma in Casimir physics

TL;DR

This mini-review argues that Casimir forces, when mediated through a high-temperature electron-positron plasma, can contribute to nuclear-scale interactions via a Casimir-Yukawa mechanism. By applying Lifshitz theory with a plasma dielectric function and Matsubara formalism, the authors relate the Casimir energy between conducting surfaces across a plasma to a Yukawa-like nuclear potential, predicting a total binding energy of about $4.5$ MeV at separations near $1$ fm and connecting this to a meson mass $m_\pi \approx (264$–$267)\,m_e$. They further provide semi-classical estimates for meson lifetimes and propose that high-temperature plasmas could bridge nuclear and mesoscopic physics, with key temperatures around $T \sim 10^{11}$–$10^{12}$ K arising for fm-scale separations. The work suggests extensions to relativistic plasma responses and spin susceptibilities, positing bound-state interpretations (e.g., mesons as electron-plasmon/positron-plasmon composites) that could revise conventional views on nuclear-force decompositions and star-core physics. Overall, the paper highlights a provocative link between Casimir physics, high-temperature plasmas, and nuclear/stellar phenomena, emphasizing the intertwined roles of density, energy, and temperature in Casimir-Yukawa effects.

Abstract

We present a short review of an unusual but important application for a high-temperature charged plasma. The unorthodox proposition was made by Ninham concerning a contribution from Casimir forces across high-temperature electron-positron plasma in nuclear interactions. The key message in the current work is how high temperatures ($\sim10^{11}$ \,K) pop out as essential. Clearly, classical, semi-classical, and quantum considerations for the background media impact both the Casimir effect and the physics of stars and the Universe.