4D cylindrical gravitational waves with aligned polarizations (Einstein-Rosen waves) are shown to be described by a weight /1/2 massive free field on the double cover of AdS<INF LOC="pre">2. Thorn's C-energy is one of the /sl(2,R) generators, the reconstruction from the (timelike) symmetry axis is the CFT<INF LOC="pre">1 holography. Classically the phase space is also invariant under a O/(1,1) group action on the metric coefficients that is a remnant of the original 4D diffeomorphism invariance. In the quantum theory this symmetry is found to be spontaneously broken while the AdS<INF LOC="pre">2 conformal invariance remains intact.
Physics Letters B
- Pub Date:
- January 2001
- High Energy Physics - Theory;
- General Relativity and Quantum Cosmology
- 13 pages, Latex, 2 Figures. v2: Figure on AdS added, minor changes