2008/02/29 by Mark Albers, Claus Kiefer, Marcel Reginatto · 1 citation
Physics and Astronomy · #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.78.064051
published as Phys.Rev.D78:064051,2008 · 31 pages, many conceptual clarifications included, new appendix added, to appear in Phys. Rev. D
arxiv created 2008/08/20 · arxiv updated 2009/12/01
We consider the question of whether consistency arguments based on measurement theory show that the gravitational field must be quantized. Motivated by the argument of Eppley and Hannah, we apply a DeWitt-type measurement analysis to a coupled system that consists of a gravitational wave interacting with a mass cube. We also review the arguments of Eppley and Hannah and of DeWitt, and investigate a second model in which a gravitational wave interacts with a quantized scalar field. We argue that one cannot conclude from the existing gedanken experiments that gravity has to be quantized. Despite the many physical arguments which speak in favor of a quantum theory of gravity, it appears that the justification for such a theory must be based on empirical tests and does not follow from logical arguments alone.