Definition of a Lorentzian Wormhole

[Falcus]

I was reading into traversable wormholes when I came across this definition from Matt Visser; 'If aMinkowski spacetimecontains a compact region Ω, and if the topology of Ω is of the form Ω ~ R × Σ, where Σ is a three-manifold of the nontrivial topology, whose boundary has topology of the form ∂Σ ~ S2, and if, furthermore, thehypersurfacesΣ are all spacelike, then the region Ω contains a quasipermanent intrauniverse wormhole'. My knowledge of relativity is extremely minimal as I am currently studying A levels. I was wondering if someone could break this down for me? I have come across a lot of the terminology before and didn't understand it at the time so thought maybe it was finally time to ask.

Thanks in advance
Falcus

 

[PeterDonis]

I came across this definition from Matt Visser

Can you give a reference to the specific article or paper? It would help to have more context.

 

[martinbn]

Can you give a reference to the specific article or paper? It would help to have more context.

I am guessing the book : Lorentzian wormholes

 

[Falcus]

I am guessing the book : Lorentzian wormholes

I believe that it is yes