Capabilities
Vacuum Spacetimes
Evolution of vacuum spacetime is provided by the McLachlan code. McLachlan solves the Einstein vacuum equations in 3D Cartesian coordinates using adaptive mesh refinement and can be combined with matter codes for modeling spacetimes containing matter. McLachlan is implemented using the Kranc package. Features of McLachlan include:
- complete implementation of the BSSNOK general relativity spacetime evolution equations including all the standard tricks that ensures stability
- up-winding for the shift advection terms
- standard moving puncture Gamma-driver and 1 + log gauges
- phi- and W- methods
- static and radiative outer boundary conditions
- inclusion of matter through the TmunuBase interface
- up to 8th order finite differencing
- OpenMP parallelization through Carpet/LoopControl in addition to MPI parallelization through Carpet
- multi-block code infrastructures by applying the Jacobian to transform local derivatives to global derivatives
Relativistic Hydrodynamics
The Einstein Toolkit GRHydro modules can evolve spacetimes with general relativistic hydrodynamics in 3D Cartesian coordinates. GRHydro is based on the public version of the Whisky code developed originally by the EU Network on Sources of Gravitational Radiation and later by a collaboration led by AEI/SISSA. Features of GRHydro include at the moment:
- Evolution of the equations of general relativistic hydrodynamics (GRHD) in 3D Cartesian coordinates on a curved dynamical background.
Initial Data
- Single and binary black holes
- Single TOV stars
- LORENE data
Relativity Tools
- Apparent horizon finding
- Black hole excision
Analysis
- TrK, det(g), R_ab, R
- ADM constraint violation
- Basic hydrodynamics analysis routines
- Extraction of gravitational waves
Computational Infrastructure
- Adaptive mesh refinement
- Reflection and rotation symmetry boundary conditions
- Radiation boundary conditions
- Flexible Cartesian 3-D meshes
- Multidimensional I/O using HDF5, ASCII, Jpegs
- Method of lines time integration
- Courant time steeping
- Seamless use of BLAS, GSL, HDF5, LAPACK
Tools
- Checking for NaNs
- Memory poisoning to identify uninitialized variables
- Timing report by thorn, schedule bin, and method