Adaptive mesh refinement for characteristic codes

The results of a feasibility study on using a transputer array to obtain a numerical solution of the characteristic initial value problem of general relativity are presented. Codes have been developed for two cases: gravity only, and gravity and matter. The testing of the codes is, so far, very limited, but timing results etc. are presented thus giving an indication of the expected performance.

http://iopscience.iop.org/article/10.1088/0264-9381/7/2/001/pdf

Numerical relativity on a transputer array

This paper brings together the theory of observational cosmology and the null-cone characteristic initial value problem (CIVP) of numerical relativity. A computer code is constructed which calculates the past behaviour of the Universe from input data that is, in principle, measurable. For practical reasons the code is limited to the case of axisymmetry without rotation. The construction of the code brings to light an interesting general point about observational cosmology. In a big-bang universe it is impossible, even in principle, to determine the state of the universe at early times. For the Einstein-de Sitter model this limit is t 0/27, where t 0 means now.

R. A. Isaacson

Papers

Numerical relativity on null cones.