# nLab coisotropic submanifold

### Context

#### Differential geometry

differential geometry

synthetic differential geometry

# Contents

## Definition

For $(X, \pi)$ a Poisson manifold, a submanifold $S \hookrightarrow X$ is called coisotropic if the restriction of the contraction map with the Poisson tensor

$\pi \;\colon \; T^* X \to T X$

to the conormal bundle $N^* S \hookrightarrow T^* S$ factors through the tangent bundle $T S$

$\pi|_{N^* S} \;\colon\; {N^* S} \to T S \hookrightarrow T X \,.$

Equivalently, $S\hookrightarrow X$ is coisotropic if the subalgebra of $C^\infty(X)$ of functions vanishing on $S$ is closed under the Poisson bracket.

## Properties

### Relation to Poisson Lie algebroids

A Poisson manifold induces a Poisson Lie algebroid, which is a symplectic Lie n-algebroid for $n = 1$. Its coisotropic submanifolds correspond to the Lagrangian dg-submanifolds (see there) of this Poisson Lie algebroid.

∞-Chern-Simons theory from binary and non-degenerate invariant polynomial

$n \in \mathbb{N}$symplectic Lie n-algebroidLie integrated smooth ∞-groupoid = moduli ∞-stack of fields of $(n+1)$-d sigma-modelhigher symplectic geometry$(n+1)$d sigma-modeldg-Lagrangian submanifold/ real polarization leaf= brane(n+1)-module of quantum states in codimension $(n+1)$discussed in:
0symplectic manifoldsymplectic manifoldsymplectic geometryLagrangian submanifoldordinary space of states (in geometric quantization)geometric quantization
1Poisson Lie algebroidsymplectic groupoid2-plectic geometryPoisson sigma-modelcoisotropic submanifold (of underlying Poisson manifold)brane of Poisson sigma-model2-module = category of modules over strict deformation quantiized algebra of observablesextended geometric quantization of 2d Chern-Simons theory
2Courant Lie 2-algebroidsymplectic 2-groupoid3-plectic geometryCourant sigma-modelDirac structureD-brane in type II geometry
$n$symplectic Lie n-algebroidsymplectic n-groupoid(n+1)-plectic geometry$d = n+1$ AKSZ sigma-model

## References

Surveys include

• Aïssa Wade, On the geometry of coisotropic submanifolds of Poisson manifolds (pdf)

The relation to the Poisson sigma-model is discussed in

Characterization in terms of leaves of Lagrangian foliation of the Poisson Lie algebroid is mentioned in

and discussed in more detail in section 7.2 of

Comments on higher algebra aspects are in the slides

Revised on March 27, 2013 19:13:51 by Urs Schreiber (89.204.154.37)