89 citations · 414 across the 18 of their papers we have counts for
6 papers · 1 filter
Quantum gravity without vacuum dispersion
Daniel Coumbe
A generic prediction of quantum gravity is the vacuum dispersion of light, and hence that a photon's speed depends on its energy. We present further numerical evidence for a scale…
Recent results in CDT quantum gravity
Jan Ambjorn, Daniel Coumbe, Jakub Gizbert-Studnicki +1
We review some recent results from the causal dynamical triangulation (CDT) approach to quantum gravity. We review recent observations of dimensional reduction at a number of previ…
What is dimensional reduction really telling us?
Daniel Coumbe
Numerous approaches to quantum gravity report a reduction in the number of spacetime dimensions at the Planck scale. However, accepting the reality of dimensional reduction also me…
Exploring the new phase transition of CDT
D. N. Coumbe, J. Gizbert-Studnicki, J. Jurkiewicz
This work focuses on the newly discovered bifurcation phase transition of CDT quantum gravity. We define various order parameters and investigate which is most suitable to study th…
Signature Change of the Metric in CDT Quantum Gravity?
Jan Ambjørn, Daniel N. Coumbe, Jakub Gizbert-Studnicki +1
We study the effective transfer matrix within the semiclassical and bifurcation phases of CDT quantum gravity. We find that for sufficiently large lattice volumes the kinetic term…
Hypothesis on the Nature of Time
D. N. Coumbe
We present numerical evidence that fictitious diffusing particles in the causal dynamical triangulation (CDT) approach to quantum gravity exceed the speed of light on small distanc…