CactusEinstein Overview
NOTE: THIS FILE IS SOMEWHAT OUT OF DATE. I WILL UPDATE IT WHEN I HAVE MORE TIME.
- Cactus Einstein
- Thorns for solving the Einstein equations of general relativity.
- ADM
- This thorn evolves the standard 3+1 variables using the ADM Evolution equations.
- ADMAnalysis
- This thorn does basic analysis of the metric and extrinsic curvature tensors.
- ADMBase
- This thorn provides the basic variables used to communicate between thorns doing General Relativity in the $3+1$ formalism.
- ADMConstraints
- This analysis thorn calculates the violation in the ADM constraints using the standard Einstein variables.
- ADMCoupling
- The "friend of a friend" thorn to help matter/spacetime coupling. Does nothing itself.
- ADMMacros
- This thorn provides nothing but a load of macros for other thorns to use.
- AHFinder
- This thorn looks for apparent horizons (AH) in 3D. An AH is defined as a surface where the expansion of outgoing null geodesics is zero.
- CoordGauge
- Base thorn to provide the infrastructure for dynamic gauge selection.
- EvolSimple
- Simplistic evolver for the ADM equations, demonstrating the use of the CactusEinstein arrangement.
This evolver evolves the physical metric, and does not contain the shift. - Extract
- Calculate gauge invariant waveforms, using the Moncrief formalism, for cases when the spacetime approximates spherical symmetry.
Calculate other quantities on a surface, such as ADM mass, momenta, and spins. - IDAnalyticBH
- This thorn calculates analytic initial data for the Einstein grid functions (lapse, shift, metric, curv) for various black hole spacetimes:
- Schwarzschild black hole
- 2 Misner black holes placed on the z-axis
- n Misner black holes placed in a circle in the x-y plane
- Brill-Lindquist data
- IDAxiBrillBH
- This thorn calculates initial data for a black hole distorted by an even parity perturbation.
- IDBrillData
- Initializes Brill wave data.
- IDLinearWaves
- Provides analytic data for linear gravitational waves.
- IDLinearWaves
- Provides analytic data for linear gravitational waves.
- IDSimple
- Simple initial data sets for 3-metric and extrinsic curvature.
Currently Minkowski in Cartesian coordinates optionally with a conformal factor. - Maximal
- This thorn setus up the maximal slicing equation (dtrK/dt=0)
- PsiKadelia
- This thorn provides a somewhat invariant means of measuring "waves" and other geometrical content in a numerically generated spacetime.
Specifically, the thorn calculates the complex scalars psi0, psi1, psi2, psi3 and psi4 with respect to a specified tetrad, and the invariants I and J. - SpaceMask
- Provides utilities for assigning states to individual grid points using a mask grid function.
- StaticConformal
- This thorn provides the variables defining a static conformal factor which is used to transform the physical metric. If this thorn is active and the ADMBase::metric_type parameter is set to `static conformal' then the ADMBase::g... variables are the conformal values as opposed to the physical values.
- timegeodesic
- This thorn integrates timelike geodesics. The integration is done `on the fly', that is, at the same time as the evolution of the spacetime is being calculated. The thorn can calculate geodesics either on the numerical spacetime, or on an exact spacetime (given by thorn Exact).
Created by
swhite
Last modified 2005-08-04 07:05 PM
Last modified 2005-08-04 07:05 PM
Cactus runs on 131,072 cores on Blue Gene/P at ANL
