I'm not sure how you're defining void cosmological models, but isn't anti-deSitter space a void cosmological model? Apparently you don't want to toss that one aside since it plays the co-star in...
Originally Posted by Selfsim
"the AdS/CFT correspondence (anti de Sitter/conformal field theory correspondence), sometimes called the Maldacena duality... the conjectured equivalence between a string theory and gravity defined on one space, and a quantum field theory without gravity defined on the conformal boundary of this space, whose dimension is lower by one or more."
...as wiki describes it. Certainly it was once a "conjecture," but isn't that what Maldacena proved...?