QED Energy-Momentum Trace as a Force in Astrophysics
  We study the properties of the trace $\Tmm$ of the QED energy-momentum tensor in the presence of quasi-constant external electromagnetic fields. We exhibit the origin of $\Tmm$ in the quantum nonlinearity of the electromagnetic theory. We obtain the quantum vacuum fluctuation-induced interaction of a particle with the field of a strongly magnetized compact stellar object. 
Lance Labun and Johann Rafelski