Collective and dynamical QED processes

A completely new possibility of doing dynamical collective vacuum physics opens up with a system such as HiPER, quite distinct from the experiments done in the particle physics community. In particular, creating an intense photon gas using micro-cavities and an array of intense laser sources and letting this gas interact with a main laser pulse from HiPER, one might be able to mimic photon propagation in the very early Universe. One can show that the collective interaction between intense photons in vacuum will generate pulse collapse scenarios in two and three dimensions. In such a pulse collapse, the intensity of the pulse theoretically grows unbounded in a finite time. It is however clear that higher order QED vacuum effects will come into play, and maybe also pair creation, at which the pulse collapse will be halted. These higher order effects are currently not well investigated, and the possibility of doing experiments on such systems would provide valuable information for further theoretical and numerical studies. A further interesting opportunity is the formation of intense filaments of pulses in the quantum vacuum. Thus, one might dynamically probe the quantum vacuum using HiPER in the same way as one has probed nonlinear optical systems over forty years with intense lasers. Although the above is speculative (not on the theoretical level however), for weakly nonlinear systems, dynamical vacuum birefringence in photon gases could also be investigated using similar setups.

Early Universe