# \poissonbracket

Used in classical mechanics and symplectic geometry to denote the Poisson bracket {f,g} of two functions

https://texform.dev/latex/commands/poissonbracket

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Physics: quantities](https://texform.dev/latex/topics/physics-quantities) |
| Packages | physics |
| Allowed mode | math |
| Tags |  |
| Commonality | low |
| Kind | prefix |

## Syntax

### physics

Argument specification: `s m{} m`

Used in classical mechanics and symplectic geometry to denote the Poisson bracket {f,g} of two functions

## Examples

```latex
\poissonbracket{f}{g}
```

[Open in Playground](https://play.texform.dev/?input=%5Cpoissonbracket%7Bf%7D%7Bg%7D)

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| physics | full | none | full |

## In TeXForm

TeXForm parses this entry as prefix syntax; the package determines its argument specification.

### Expands to (physics)

```latex
\poissonbracket{f}{g}
```

→

```latex
\left\{f,g\right\}
```

With star: \{f,g\} without \left/\right. With optional \big, \Big, \bigg, or \Bigg prefix: uses corresponding \bigl\{...\bigr\} sizing.

## See also

- [\\acomm](https://texform.dev/latex/commands/acomm)
- [\\anticommutator](https://texform.dev/latex/commands/anticommutator)
- [\\comm](https://texform.dev/latex/commands/comm)
- [\\commutator](https://texform.dev/latex/commands/commutator)
- [\\pb](https://texform.dev/latex/commands/pb)

## Test cases

### physics

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \poissonbracket{a}{b} | Positive: baseline | Pass | Fail | Pass |
| \poissonbracket*{a}{b} | Positive: vary:s[0] | Pass | Fail | Pass |
| \poissonbracket{a}b | Positive: bare[2] | Pass | Fail | Pass |