The null energy condition in wormholes with cosmological constant

Dynamic and static wormhole solutions of Einsteins equations with the cosmological constant are presented. The dynamic solutions can be interpreted as Friedmann–Robertson–Walker models with traversable wormholes. The null energy condition is checked for both dynamic and static wormholes and it is shown explicitly that the cosmological constant modifies the violation of this condition.     

Experimental Test for Extra Dimensions in Kaluza–Klein Gravity

5D Kaluza–Klein gravity has several nonasymptotically flat solutions which generally, possess both electric and magnetic charges. In this paper we suggest that these solutions can act as quantum virtual handles (wormholes) in spacetime foam models. In the presence of a sufficently large, external electric and/or magnetic field it may be possible to inflate these solutions from a quantum to a classical state. This effect would lead to a possible experimental signal for higher dimensions in multidimensional gravity.