The functional integral of pure Einstein 4D quantum gravity admits abnormally large and long-lasting “dipolar fluctuations”, generated by virtual sources with the property

4D Einstein gravity coupled to scalars and abelian gauge fields in its 2-Killing vector reduction is shown to be quasi-renormalizable to all loop orders at the expense of introducing infinitely many essential couplings. The latter can be combined into one or two functions of the ‘area radius’ associated with the two Killing vectors. The renormalization flow of these couplings is governed by bet...

The multidimensional gravity on principal bundle with structural SU (2) gauge group is considered. The Lorentzian wormhole solution disposed between two event horizons is founded in this case. In some sense this wormhole is dual to the black hole in 4D Einstein-Yang-Mills gravity (sphaleron): they are located at different sides of the event horizon.

We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time with a Z 2 symmetry in the presence of a massless scalar field. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane (brane cosmological constant) by, for instance, electroweak and QCD phase transitions, just gives rise to dynamical shifts of ...