Spectral dimension on spatial hypersurfaces in causal set quantum gravity

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...

The Spectral Dimension of 2D Quantum Gravity

We show that the spectral dimension ds of two-dimensional quantum gravity coupled to Gaussian fields is two for all values of the central charge c ≤ 1. The same arguments provide a simple proof of the known result ds = 4/3 for branched polymers. email [email protected] email [email protected] email [email protected] email [email protected] email [email protected] 1

A Covariant Causal Set Approach to Discrete Quantum Gravity

A covariant causal set (c-causet) is a causal set that is invariant under labeling. Such causets are well-behaved and have a rigid geometry that is determined by a sequence of positive integers called the shell sequence. We first consider the microscopic picture. In this picture, the vertices of a c-causet have integer labels that are unique up to a label isomorphism. This labeling enables us t...