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Child Universe Production

Eduardo Guendelman (Ben Gurion University)
03 July 2007, 14:30 - 16:15

Inflationary cosmology proposes that in the early universe a false vacuum, that is a phase of matter with equation of state pressure = - energy density existed. This produces an exponential expansion of the early universe, solving many important cosmological problems, like the flatness problem, the horizon problem, etc. In my talk I will deal with the consideration of a bubble of false vacuum that could be formed in our present Universe. This leads to interesting questions: The false vacuum bubble has an energy density which is higher than the sourrounding space. Because of this, although the space inside the bubble can undergo an exponential expansion, the pressre difference with respect to the outside implies the bubble cannot displace the external space. What is obtained instead is the child universe solution, where a new universe is created which disconnects from the exterior region. These solutions contain a wormhole region and also a white hole singularity, a sort of local big bang singularity. Different scenarios that avoid the initial singularity will be discussed. These could be quantum, like tunneling from a particle like , classically stable configuration to other classical processes, but that circumvent relevant singularity theorems. The possibility of child universe production in particle accelerators will be discussed. Finally I will argue that child universes production is unsupressed at transplanckian scales and the possible relevance of this for quantum gravity.
Guendelman.pdf [4657 KBytes]