Caramba! Wormholes and Catflaps

Dear Friends - Worm Holes and Cat Flaps

Table of contents

I Introduction II Black Holes and big bangs in contrast p.2 III A black hole universe p.6

IV Gravitational collapse p.8 V Black hole escape velocity p.10 VI The radius of a black hole p.14

VII Metric 'extensions' p.20 VIII Black hole universes p.28 IX Big bang universes p.33

X Gravitational waves and conservation laws p.34 XI Functional analysis p.40 Appendix A: Gaussian curvature p.40

Appendix B: Riemannian curvature p.49 Appendix C: Acceleration invariant p.64 Appendix D: Isotropic coordinates p.67

Appendix E: The Kretschmann scalar p.92 Appendix F: Geodesic completeness p.97