# Large quantum gravity effects: Unforeseen limitations of the classical theory

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61 Scopus citations

### Abstract

3-dimensional gravity coupled to Maxwell (or Klein-Gordon) fields is exactly soluble under the assumption of axi-symmetry. The solution is used to probe several quantum gravity issues. In particular, it is shown that the quantum fluctuations in the geometry are large unless the number and frequency of photons satisfy the inequality $\N(\hbar G\omega)^2 ≪ 1$. Thus, even when there is a single photon of Planckian frequency, the quantum uncertainties in the metric are significant. Results hold also for a sector of the 4-dimensional theory (consisting of Einstein Rosen gravitational waves).

Original language English (US) 4864-4867 4 Physical Review Letters 77 24 https://doi.org/10.1103/PhysRevLett.77.4864 Published - Jan 1 1996

### All Science Journal Classification (ASJC) codes

• Physics and Astronomy(all)