Neat submanifold explained

In differential topology, an area of mathematics, a neat submanifold of a manifold with boundary is a kind of "well-behaved" submanifold.

To define this more precisely, first let

M

be a manifold with boundary, and

A

be a submanifold of

M

.

Then

A

is said to be a neat submanifold of

M

if it meets the following two conditions:[1]

A

is a subset of the boundary of

M

. That is,

\partialA\subset\partialM

.

A

has a neighborhood within which

A

's embedding in

M

is equivalent to the embedding of a hyperplane in a higher-dimensional Euclidean space.

More formally,

A

must be covered by charts

(U,\phi)

of

M

such that

A\capU=\phi-1(Rm)

where

m

is the dimension For instance, in the category of smooth manifolds, this means that the embedding of

A

must also be smooth.

See also

Notes and References

  1. .