Subbundle Explained

In mathematics, a subbundle

L

of a vector bundle

E

over a topological space

M

is a subset of

E

such that for each

x

in

M,

the set

Lx

, the intersection of the fiber

Ex

with

L

, is a vector subspace of the fiber

Ex

so that

L

is a vector bundle over

M

in its own right.

In connection with foliation theory, a subbundle of the tangent bundle of a smooth manifold may be called a distribution (of tangent vectors).

If locally, in a neighborhood

Nx

of

x\inM

, a set of vector fields

Yk

span the vector spaces

Ly,y\inNx,

and all Lie commutators

\left[Yi,Yj\right]

are linear combinations of

Y1,...,Yn

then one says that

L

is an involutive distribution