Effects of spacetime fluctuations

• Applicant: Professor Dr. Claus Lämmerzahl
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2009 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 91114040

A theory of quantum gravity is far from being complete and experimental verifiable predictions of loop quantum gravity and string theory are still lacking. However, some general predictions are made by such approaches. In quantum gravity phenomenology the missing link between theoretical approach and experiment is overcome by working out possible scenarios in which some physical features are violated. The experimental techniques, necessary for the verification of such phenomenological models, have reached a high level of accuracy and are continuously developed further.The objective of this project is to extend a special model for space-time fluctuations, being a possible outcome of a underlying quantum theory of gravitation. This includes the application of the model to different branches of physics, namely the fermionic sector, photons and macroscopic quantum systems like Bose-Einstein condensates. This leads to modified Maxwell-equations, a modified Dirac equation, the appearance of decoherence and to a modified Gross-Pitaevski equation, where deviations from standard-physics are parameterized within the approach. By comparing with high-sensitivity experiments in the laboratory (e.g. Bose-Einstein condensates, matter-wave interferometry and Michelson-Morley type experiments) and with astrophysical observations (e.g. gamma-ray bursts), this approach allows to set quantitative bounds on possible modifications. The work to be done would lead to a comprehensive - of course not complete - overview over implications of space-time fluctuations on quantum- and classical systems. This is necessary in order to assist in the search for a theory of quantum gravity.

• DFG Programme: Research Grants