We study quantum gravity in more than four dimensions by means of an exact functional flow. A non-trivial ultraviolet fixed point is found in the Einstein–Hilbert theory. It is shown that our results for the fixed point and universal scaling exponents are stable. If the fixed point persists in extended truncations, quantum gravity in the metric field is asymptotically safe. We indicate physical...

We study the interior structure of five dimensional neutral helical black holes in Einstein gravity and charged Einstein-Maxwell gravity. Inside holes, systems evolve to a stable spacelike Kasner singularity. The metric field related deformation strength exhibits oscillation behavior close horizon at low temperature small strength. we show that inner Cauchy can not exist. also from find oscilla...

The successful explanation of cosmological puzzles, such as the horizon, flatness, and monopole problems, is achieved by the inflationary scenarios. The inflationary scenarios also predict the spectrum of the density perturbation which seeds the formation of the large scale structure of the Universe. The basic assumption is that, at the early times, the Universe experienced an accelerated expan...

I discuss the relation between arbitrarily high-order theories of gravity and scalartensor gravity at the level of the field equations and the action. I show that (2n+4)-order gravity is dynamically equivalent to Brans-Dicke gravity with an interaction potential for the Brans-Dicke field and n further scalar fields. This scalar-tensor action is then conformally equivalent to the Einstein-Hilber...

I review how " classical SUGRA " embeddability establishes positive energy E for D = 3 topologically massive gravity (TMG), with or without a cosmological term, a procedure familiar from D = 4 Einstein gravity (GR). It also provides explicit expressions for E. In contrast to GR, E is not manifestly positive, due to the peculiar two-term nature of TMG.

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.

The problem of explaining the acceleration of the expansion of the universe and the observational and theoretical difficulties associated with dark matter and dark energy are discussed. The possibility that Einstein gravity does not correctly describe the large-scale structure of the universe is considered and an alternative gravity theory is proposed as a possible resolution to the problems. e...

A general framework for the solutions of the constraints of pure gravity is constructed. It provides with well defined mathematical criteria to classify their solutions in four classes. Complete families of solutions are obtained in some cases. A starting point for the systematic study of the solutions of Einstein gravity is suggested.

Einstein field equations with a cosmological constant are linearized assuming a flat background metric. The final result is a set of EinsteinMaxwell-Proca equations for gravity in the weak field approximation. This linearization procedure implements the breaking of gauge symmetry in general relativity. A brief discussion of the physical consequences is proposed in the framework of the gauge the...

A general framework for the solutions of the constraints of pure gravity is constructed. It provides with well defined mathematical criteria to classify their solutions in four classes. Complete families of solutions are obtained in some cases. A starting point for the systematic study of the solutions of Einstein gravity is suggested.