Mathieu transformation

The Mathieu transformations make up a subgroup of canonical transformations preserving the differential form

The transformation is named after the French mathematician Émile Léonard Mathieu.

In order to have this invariance, there should exist at least one relation between ${\displaystyle q_{i}}$ and ${\displaystyle Q_{i}}$ only (without any ${\displaystyle p_{i},P_{i}}$ involved).

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