Creating Constraint Violating Initial Data

Gabrielle Allen

Date

Abstract

The IDConstraintViolate thorn creates initial data which purposefully violates the constraint equations for testing purposes.

1 Gaussian

Choosing the ADMBase parameter initial_data to have the value Constraint violating gaussian creates initial data with the form

gxx = gyy = gzz = 1 + Aexp (r r0)2 σ2 gxy = gxz = gyz = 0 Kij = 0

where the size and shape of the Gaussian is specified by parameters, A=amplitude, r0=radius and σ=sigma.

2 Parameters




amplitude
Scope: private  REAL



Description: The amplitude of the waves



Range   Default: 0.001
*:*
No restriction






radius
Scope: private  REAL



Description: The radial position of the Gaussian wave



Range   Default: 0.0
0:*
Positive






sigma
Scope: private  REAL



Description: The sigma for the Gaussian wave



Range   Default: 0.1
(0:*
Positive






initial_data
Scope: shared from ADMBASE  KEYWORD



Extends ranges:



see [1] below
Constraint violating Gaussian



[1]

constraint violating gaussian




metric_type
Scope: shared from ADMBASE KEYWORD



3 Interfaces

General

Implements:

idconstraintviolate

Inherits:

admbase

grid

4 Schedule

This section lists all the variables which are assigned storage by thorn EinsteinInitialData/IDConstraintViolate. Storage can either last for the duration of the run (Always means that if this thorn is activated storage will be assigned, Conditional means that if this thorn is activated storage will be assigned for the duration of the run if some condition is met), or can be turned on for the duration of a schedule function.

Storage

NONE

Scheduled Functions

CCTK_PARAMCHECK

  idconstraintviolate_paramchecker

  check parameters

 

 Language:c
 Type: function

ADMBase_InitialData

  idconstraintviolate_initial

  set up constraint violating initial data

 

 Language:fortran
 Type: function