# nLab Lie derivative

### Context

#### Differential geometry

differential geometry

synthetic differential geometry

∞-Lie theory

# Contents

## Idea

Given a smooth manifold $M$ and a vector field $X \in \Gamma(T M)$ on it, one defines a series of operators $\mathcal{L}_X$ on spaces of differential forms, of functions, of vector fields and multivector fields. For functions $\mathcal{L}_X(f) = X(f)$ (derivative of $f$ along an integral curve of $X$); as multivector fields and forms can not be compared in different points, one pullbacks or pushforwards them to be able to take a derivative.

For vector fields $\mathcal{L}_X Y = [X,Y]$. If $\omega \in \Omega^\bullet(M)$ is a differential form on $M$, the Lie derivative $\mathcal{L}_X \omega$ of $\omega$ along $X$ is the linearization of the pullback of $\omega$ along the flow $\exp(X -) : \mathbb{R} \times M\to M$ induced by $X$

$\mathcal{L}_X \omega = \frac{d}{d t}|_{t = 0} \exp(t X)^*(\omega) \,.$

Denote by $\iota_X : \Omega^\bullet(M) \to \Omega^{\bullet -1}(M)$ be the graded derivation which is the contraction with a vector field $X$. By Cartan's homotopy formula,

$\mathcal{L}_v = [d_{dR}, \iota_v] = d_{dR} \circ \iota_v + \iota_v \circ d_{dR} : \Omega^\bullet(X) \to \Omega^\bullet(X) \,.$

## References

An introduction in the context of synthetic differential geometry is in

• Gonzalo Reyes, Lie derivatives, Lie brackets and vector fields over curves, pdf

A gentle elementary introduction for mathematical physicists

• Bernard F. Schutz, Geometrical methods of mathematical physics (elementary intro) amazon, google

.

Revised on September 1, 2011 21:00:48 by Zoran Škoda (161.53.130.104)