NB: This question comes from an idea I had while watching this video about the video game portal and its sequel (link: https://www.youtube.com/watch?v=aj8NDOA0Sgw at 15:30 the idea of a black hole was discussed)
If large positive density creates a black hole, would large negative density (created from negative mass over a positive area) create a white hole?
Furthermore, if this is true, would the perpetual output of a white hole 'feed' the perpetual input of a black hole (assuming they are arranged in a way that the white hole spews into the black hole) so that nothing else is absorbed by the black hole?