Finite size scaling in 2d causal set quantum gravity

Scaling and Quantum Geometry in 2d Gravity

The geometry of quantum spacetime of 2d gravity in the presence of conformal matter with c ≤ 1 is the last important problem in those models which is not yet fully understood. Although it is quite clear [1] that pure gravity (c=0) gives rise to a fractal structure with Hausdorff dimension dh = 4 which becomes manifest by the self similar distribution of geodesic boundary loop lengths at all geo...

Counting entropy in causal set quantum gravity

The finiteness of black hole entropy suggest that spacetime is fundamentally discrete, and hints at an underlying relationship between geometry and ”information”. The foundation of this relationship is yet to be uncovered, but should manifest itself in a theory of quantum gravity. We review recent attempts to define a microscopic measure for black hole entropy and for the maximum entropy of sph...

The Causal Set Approach to Quantum Gravity

The causal set approach to quantum gravity

The ideas of spacetime discreteness and causality are important in several of the popular approaches to quantum gravity. But if discreteness is accepted as an initial assumption, conflict with Lorentz invariance can be a consequence. The causal set is a discrete structure which avoids this problem and provides a possible history space on which to build a “path integral” type quantum gravity the...

Choptuik scaling and Quantum effects in 2D Dilaton Gravity

We study numerically the collapse of massless scalar fields in two-dimensional dilaton gravity, both classically and semiclassically. At the classical level, we find that the black hole mass scales at threshold like Mbh ∝ |p − p∗|γ , where γ ≃ 0.53. At the semiclassical level, we find that in general Mbh approaches a non-zero constant as p → p. Thus, quantum effects produce a mass gap not prese...