The Hartle-Hawking wave function in 2d causal set quantum gravity
Abstract
We define the Hartle-Hawking no-boundary wave function for causal set theory (CST) over the discrete analogs of spacelike hypersurfaces. Using Markov Chain Monte Carlo and numerical integration methods we analyse the wave function in non- perturbative 2d CST. We find that in the low temperature regime it is dominated by causal sets which have no continuum counterparts but possess physically interesting geometric properties. Not only do they exhibit a rapid spatial expansion with respect to the discrete proper time but also a high degree of spatial homogeneity. The latter is due to the extensive overlap of the causal pasts of the elements in the final discrete hypersurface and corresponds to high graph connectivity. Our results thus suggest new possibilities for the role of quantum gravity in the observable universe.
Cite
@article{arxiv.1410.8775,
title = {The Hartle-Hawking wave function in 2d causal set quantum gravity},
author = {Lisa Glaser and Sumati Surya},
journal= {arXiv preprint arXiv:1410.8775},
year = {2015}
}
Comments
29 pages, 16 figures, v3 The paper has been expanded considerably with the inclusion of more data and the conclusions have been made more explicit v4 online abstract fixed