We discuss the problem of a degenerate vierbein in the framework of gauge theories of gravitation (thus including torsion). We discuss two examples: Hanson-Regge gravitational instanton and Einstein-Rose bridge.We argue that a region of space-time with vanishing vierbein but smooth principal connection can be, in principle, detected by scattering experiments.
- Pub Date:
- September 1999
- General Relativity and Quantum Cosmology
- Latex format. 15 pages, 2 figures in gif format, available also for downloads at http://www.cassiopaea.org/images/traj.gif and http://www.cassiopaea.org/images/bubble.gif respectively. This paper has been published as a preprint 1n 1982. After so many years I decided to make it available for a wider public, to include 1984 referee report with my comments, and also to add reference to a more recent work on degenerate metric, where this paper is quoted