Document Type

Article

Journal/Book Title/Conference

General Relativity and Gravitation

Volume

42

Issue

6

Publisher

Springer

Publication Date

7-2009

DOI

10.1007

Abstract

We construct Penrose diagrams for Schwarzschild spacetimes joined by massless shells of matter, in the process correcting minor flaws in the similar diagrams drawn by Dray and ’t Hooft (Commun Math Phys 99:613–625, 1985), and confirming their result that such shells generate a horizon shift. We then consider shells with negative energy density, showing that the horizon shift in this case allows for travel between the heretofore causally separated exterior regions of the Schwarzschild geometry. These drawing techniques are then used to investigate the properties of successive shells, joining multiple Schwarzschild regions. Again, the presence of negative-energy shells leads to a causal connection between the exterior regions, even in (some) cases with two successive shells of equal but opposite total energy.

Comments

Originally published by Springer. The original publication is available at:

http://www.springerlink.com/content/a384182p1h671hq5/

http://www.springerlink.com