Causal Set Generator and Action Computer

Abstract

The causal set approach to quantum gravity has gained traction over the past three decades, but numerical experiments involving causal sets have been limited to relatively small scales. The software suite presented here provides a new framework for the generation and study of causal sets. Its efficiency surpasses previous implementations by several orders of magnitude. We highlight several important features of the code, including the compact data structures, the $O(N^2)$ causal set generation process, and several implementations of the $O(N^3)$ algorithm to compute the Benincasa-Dowker action of compact regions of spacetime. We show that by tailoring the data structures and algorithms to take advantage of low-level CPU and GPU architecture designs, we are able to increase the efficiency and reduce the amount of required memory significantly. The presented algorithms and their implementations rely on methods that use CUDA, OpenMP, x86 Assembly, SSE/AVX, Pthreads, and MPI. We also analyze the scaling of the algorithms' running times with respect to the problem size and available resources, with suggestions on how to modify the code for future hardware architectures.

14 pages, 6 figures. Code may be downloaded at <https://bitbucket.org/dk-lab/causalsetgenerator>

References in corpus (7)

• Causal Sets: Discrete Gravity (Notes for the Valdivia Summer School)
• Generalized Causal Set d'Alembertians
• Directions in Causal Set Quantum Gravity
• Emergence of spatial structure from causal sets
• Causal Sets: Quantum gravity from a fundamentally discrete spacetime
• A 2D model of Causal Set Quantum Gravity: The emergence of the continuum
• The Random Discrete Action for 2-Dimensional Spacetime

Cited by in corpus (7)

• Quantum Gravity from Causal Dynamical Triangulations: A Review
• Dimensionally Restricted Causal Set Quantum Gravity: Examples in Two and Three Dimensions
• Steps towards Lorentzian quantum gravity with causal sets
• On the Entanglement Entropy of Quantum Fields in Causal Sets
• Discrete Spacetime: a Web of Chains
• Phase transitions in 2d orders coupled to the Ising model
• High Performance Algorithms for Quantum Gravity and Cosmology