Title: Particle creation in a toroidal universe Authors: Bartosz Fornal
We calculate the particle production rate in an expanding universe with a three-torus topology. We discuss also the complete evolution of the size of such a universe. The energy density of particles created through the nonzero modes is computed for selected masses. The unique contribution of the zero mode and its properties are also analysed.
Quantum quirk may reveal early universe A tabletop experiment to mimic conditions in the early universe could steal some thunder from the Large Hadron Collider (LHC), the worlds largest particle smasher. As the hot infant universe rapidly expanded, cosmologists believe that particles were created from the vacuum of empty space. To find out how, physicists generally use giant accelerators like the LHC currently being built at CERN in Switzerland to generate the kind of energies that existed soon after the big bang. Now Ralf Schützhold at Dresden University of Technology in Germany and his colleagues are proposing a considerably cheaper and easier experiment.
We could potentially probe the conditions of the universe at times stretching back beyond the reach of the LHC - Ralf Schützhold .
The teams method relies on a quirk of quantum mechanics. Just as light waves can be thought of as a series of photon particles, sound waves moving through ions in a solid can be thought of as a beam of phonon particles. According to the teams calculations, the same quantum processes that gave rise to photons and other particles in the early universe should create pairs of phonons in a cloud of ions in the lab.
Title: Analogue of cosmological particle creation in an ion trap Authors: Ralf Schützhold, Michael Uhlmann, Lutz Petersen, Hector Schmitz, Axel Friedenauer, Tobias Schätz
We study phonons in a dynamical chain of ions confined by a trap with a time-dependent (axial) potential strength and demonstrate that they behave in the same way as quantum fields in an expanding/contracting universe. Based on this analogy, we present a scheme for the detection of the analogue of cosmological particle creation which should be feasible with present-day technology. In order to test the quantum nature of the particle creation mechanism and to distinguish it from classical effects such as heating, we propose to measure the two-phonon amplitude via the 2^{ m nd} red side-band and to compare it with the one-phonon amplitude (1^{ m st} red side-band). PACS: 04.62.+v, 98.80.-k, 42.50.Vk, 32.80.Pj.