# Scalar functions for wave extraction in numerical relativity

## Abstract

Wave extraction plays a fundamental role in the binary black hole simulations currently performed in numerical relativity. Having a well-defined procedure for wave extraction, which matches simplicity with efficiency, is critical especially when comparing waveforms from different simulations. Recently, progress has been made in defining a general technique which uses Weyl scalars to extract the gravitational wave signal, through the introduction of the quasi-Kinnersley tetrad. This procedure has been used successfully in current numerical simulations; however, it involves complicated calculations. The work in this paper simplifies the procedure by showing that the choice of the quasi-Kinnersley tetrad is reduced to the choice of the timelike vector used to create it. The spacelike vectors needed to complete the tetrad are then easily identified, and it is possible to write the expression for the Weyl scalars in the right tetrad, as simple functions of the electric and magnetic parts of the Weyl tensor.

- Authors:

- Center for Relativity, University of Texas at Austin, Austin Texas 78712-1081 (United States)

- Publication Date:

- OSTI Identifier:
- 20935254

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevD.75.104002; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BLACK HOLES; FUNCTIONS; GRAVITATIONAL WAVES; RELATIVITY THEORY; SCALARS; SIGNALS; SIMULATION; VECTORS; WAVE FORMS

### Citation Formats

```
Nerozzi, Andrea.
```*Scalar functions for wave extraction in numerical relativity*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.104002.

```
Nerozzi, Andrea.
```*Scalar functions for wave extraction in numerical relativity*. United States. doi:10.1103/PHYSREVD.75.104002.

```
Nerozzi, Andrea. Tue .
"Scalar functions for wave extraction in numerical relativity". United States.
doi:10.1103/PHYSREVD.75.104002.
```

```
@article{osti_20935254,
```

title = {Scalar functions for wave extraction in numerical relativity},

author = {Nerozzi, Andrea},

abstractNote = {Wave extraction plays a fundamental role in the binary black hole simulations currently performed in numerical relativity. Having a well-defined procedure for wave extraction, which matches simplicity with efficiency, is critical especially when comparing waveforms from different simulations. Recently, progress has been made in defining a general technique which uses Weyl scalars to extract the gravitational wave signal, through the introduction of the quasi-Kinnersley tetrad. This procedure has been used successfully in current numerical simulations; however, it involves complicated calculations. The work in this paper simplifies the procedure by showing that the choice of the quasi-Kinnersley tetrad is reduced to the choice of the timelike vector used to create it. The spacelike vectors needed to complete the tetrad are then easily identified, and it is possible to write the expression for the Weyl scalars in the right tetrad, as simple functions of the electric and magnetic parts of the Weyl tensor.},

doi = {10.1103/PHYSREVD.75.104002},

journal = {Physical Review. D, Particles Fields},

number = 10,

volume = 75,

place = {United States},

year = {Tue May 15 00:00:00 EDT 2007},

month = {Tue May 15 00:00:00 EDT 2007}

}