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nmen

nmen is a term used in speculative discussions of geometry to denote a hypothetical class of objects that generalize ordinary n-dimensional manifolds by incorporating extra local data. An nmen consists of a topological space M of dimension n together with an auxiliary local structure defined on charts and compatible on overlaps.

The added data can take several forms, such as a sheaf, a group action, or a system

Variants of nmen are used in pedagogy to illustrate how local refinements interact with global geometry. Examples

Despite these illustrations, nmen is not a standard object in mainstream mathematics and appears mainly in

See also: manifold, n-manifold, orbifold, sheaf.

of
local
invariants.
In
the
simplest
interpretation,
the
extra
data
is
trivial,
and
every
ordinary
n-manifold
is
an
nmen.
Nontrivial
data
may
influence
global
properties
without
altering
the
underlying
topology.
include
decorated
or
colored
n-manifolds,
or
orbifold-like
objects
where
the
local
structure
encodes
symmetry.
expository
or
speculative
contexts.
It
serves
as
a
conceptual
tool
rather
than
a
canonical
research
subject.