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regular covering (Definition)
Theorem 1   Let $p\co E\to X$ be a covering map where $E$ and $X$ are connected and locally path connected and let $X$ have a basepoint $*$ . The following are equivalent:
  1. The action of $\Au(p)$ , the group of covering transformations of $p$ , is transitive on the fiber $p^{-1}(*)$ ,
  2. for some $e\in p^{-1}(*)$ , $p_*\left(\pi_1(E,e)\right)$ is a normal subgroup of $\pi_1(X,*)$ , where $p_*$ denotes $\pi_1(p)$ ,
  3. $\forall e,e'\in p^{-1}(*), \quad p_*\left(\pi_1(E,e)\right)=p_* \left(\pi_1(E,e')\right)$ ,
  4. there is a discrete group $G$ such that $p$ is a principal $G$ -bundle.
All the elements for the proof of this theorem are contained in the articles about the monodromy action and the deck transformations.
Definition 2   A covering with the properties described in the previous theorem is called a regular or normal covering. The term Galois covering is also used sometimes.




"regular covering" is owned by Dr_Absentius.
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Other names:  normal covering, Galois covering
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Cross-references: term, normal, regular, properties, covering, deck transformations, monodromy action, contained, theorem, proof, group, discrete, normal subgroup, fiber, transitive, group of covering transformations, action, the following are equivalent, basepoint, locally path connected, connected, covering map
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This is version 3 of regular covering, born on 2003-02-12, modified 2004-01-24.
Object id is 4027, canonical name is RegularCovering.
Accessed 6807 times total.

Classification:
AMS MSC55R05 (Algebraic topology :: Fiber spaces and bundles :: Fiber spaces)

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