Title:	Dimensionally restricted causal set quantum gravity: examples in two and three dimensions
Authors:	Cunningham, William J Surya, Sumati
Keywords:	quantum gravity causal set theory numerics
Issue Date:	7-Feb-2020
Publisher:	IOP Publishing Ltd.
Citation:	Classical and Quantum Gravity, 2020, Vol.37, p054002
Abstract:	We study dimensionally restricted non-perturbative causal set quantum dynamics in 2 and 3 spacetime dimensions with non-trivial global spatial topology. The causal set sample space is generated from causal embeddings into spacetime lattices with global spatial topology S1 and T2 in 2 and 3 dimensions, respectively. The quantum gravity partition function over these sample spaces is studied using Markov Chain Monte Carlo (MCMC) simulations after analytic continuation. In both 2 and 3 dimensions we find a phase transition that separates the dominance of the action from that of the entropy. The action dominated phase is characterised by ``layered'' posets with a high degree of connectivity, while the causal sets in the entropy dominated phase are manifold-like. This phase transition is similar in character to that seen for the sample space of 2 -orders, which are topologically trivial, hence suggesting that this is a generic feature of dimensionally restricted sample spaces. The simulations use a newly developed framework for causal set MCMC calculations. Ours is the first implementation of a causal set dynamics restricted to 3 dimensions.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/7453
ISSN:	0264-9381 1361-6382 (E)
Alternative Location:	https://ui.adsabs.harvard.edu/abs/2019arXiv190811647C/abstract https://arxiv.org/abs/1908.11647 https://doi.org/10.1088/1361-6382/ab60b7
Copyright:	2020 IOP Publishing Ltd.
Appears in Collections:	Research Papers (TP)

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