An efficient algorithm for the Riemannian 10j symbols
Abstract
The 10j symbol is a spin network that appears in the partition function for the BarrettCrane model of Riemannian quantum gravity. Elementary methods of calculating the 10j symbol require O(j^{9}) or more operations and O(j^{2}) or more space, where j is the average spin. We present an algorithm that computes the 10j symbol using O(j^{5}) operations and O(j^{2}) space, and a variant that uses O(j^{6}) operations and a constant amount of space. An implementation has been made available on the web.
 Publication:

Classical and Quantum Gravity
 Pub Date:
 March 2002
 DOI:
 10.1088/02649381/19/6/310
 arXiv:
 arXiv:grqc/0110045
 Bibcode:
 2002CQGra..19.1185C
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 9 pages, 5 postscript figures. This is the version that is to appear in Classical and Quantum Gravity. See also http://jdc.math.uwo.ca/spinfoams