Non-perturbative spectrum of non-local gravity

(Non)perturbative gravity, nonlocality, and nice slices

Perturbative dynamics of gravity is investigated for high energy scattering and in black hole backgrounds. In the latter case, a straightforward perturbative analysis fails, in a close parallel to the failure of the former when the impact parameter reaches the Schwarzschild radius. This suggests a flaw in a semiclassical description of physics on spatial slices that intersect both outgoing Hawk...

Non-perturbative 3d Lorentzian Quantum Gravity

We have recently introduced a discrete model of Lorentzian quantum gravity, given as a regularized non-perturbative state sum over simplicial Lorentzian spacetimes, each possessing a unique Wick rotation to Euclidean signature. We investigate here the phase structure of the Wick-rotated path integral in three dimensions with the aid of computer simulations. After fine-tuning the cosmological co...

Non-Perturbative Two-Dimensional Quantum Gravity, Again

Non - perturbative Gravity , Hagedorn Bounce & CMB

In [1] it was shown how non-perturbative corrections to gravity can resolve the big bang singularity, leading to a bouncing universe. Depending on the scale of the nonperturbative corrections, the temperature at the bounce may be close to or higher than the Hagedorn temperature. If matter is made up of strings, then massive string states will be excited near the bounce, and the bounce will occu...

Non-perturbative Solutions for Lattice Quantum Gravity

We propose a new, discretized model for the study of 3+1-dimensional canonical quantum gravity, based on the classical SL(2,C)-connection formulation. The discretization takes place on a topological N3-lattice with periodic boundary conditions. All operators and wave functions are constructed from one-dimensional link variables, which are regarded as the fundamental building blocks of the theor...