Dynamic wormholes

A new framework is proposed for general dynamic wormholes, unifying them wi th black holes. Both are generically defined locally by outer trapping hori zons, temporal for wormholes and spatial or null for black and white holes. Thus wormhole horizons are two-way traversible, while blackhole and whiteh ole horizons are only one-way traversible. It follows from the Einstein equ ation that the null energy condition is violated everywhere on a generic wo rmhole horizon. It is suggested that quantum inequalities constraining nega tive energy break down at such horizons. Wormhole dynamics can be developed as for blackhole dynamics, including a reversed second law and a first law involving a definition of wormhole surface gravity. Since the causal natur e of a horizon can change, being spatial under positive energy and temporal under sufficient negative energy, blackholes and wormholes are interconver tible. In particular, if a wormhole's negative-energy source fails, it may collapse into a blackhole. Conversely, irradiating a blackhole horizon with negative energy could convert it into a wormhole horizon. This also sugges ts a possible final state of blackhole evaporation: a stationary wormhole. The new framework allows a fully dynamical description of the operation of a wormhole for practical transport, including the back-reaction of the tran sported matter on the wormhole. As an example of a matter model, a Klein-Go rdon field with negative gravitational coupling is a source for a static wo rmhole of Morris and Thorne.