Double cover
In mathematics, a double cover or double covering may refer to:

Double cover (topology), a twotoone mapping from one topological space to another. Frequently occurring special cases include
 The orientable double cover of a nonorientable manifold
 The bipartite double cover of an undirected graph G, formed by the graph tensor product G ×K_{2}
 A double covering group of a topological group such as a Lie group, a group extension of index two formed by a topological double cover. A double cover may also be used to refer to nontopological group extensions of index two, for instance extensions of finite groups.
 Cycle double cover, a collection of cycles in a graph that together include each edge twice. The cycle double cover conjecture is the unproven assertion that every bridgeless graph has a cycle double cover.
Double coverage may also refer to:
 Double coverage, a defensive strategy in American football, basketball, and other sports
 Being covered by more than one health insurance plan
 A type of Asphalt roll roofing.
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