Parallel Linear General Relativity and CMB Anisotropies

We have developed a code which links the primeval fluctuations in the early universe with those observable at the present time by integrating the coupled, linearized, Einstein, Boltzmann, and fluid equations governing the evolution of metric perturbations and density fluctuations; this is the most accurate treatment to date of both the physics and the numerical integration. The results are useful both for calculations of the cosmic microwave background (CMB) anisotropy and the linear power spectrum of matter fluctuations. The serial code (LINGER) is highly efficient on vector machines. Furthermore, this application is perfectly suited for coarse-grained parallelism. A portable, parallel implementation (PLINGER) using common message-passing libraries (PVM, MPI, MPL, and PVMe) has been completed; it achieves Gflop/sec rates on current parallel supercomputers such as the T3D and SP2. LINGER and PLINGER are publically available as part of the COSMICS software package.