Orphan

Local topological group

A local topological group or local group is a topological space which behaves like a topological group sufficiently close to a distinguished identity element. topology Formally a local group (𝑋,T,𝑒,Θ,Ξ©,𝑖,π‘š) consists of a topological space (𝑋,T), open subets Θ βŠ†πΊ and Ξ© βŠ†πΊ ×𝐺, a distinguished identity element 𝑒 ∈Θ βŠ†πΊ, and continuous functions 𝑖 :Θ β†’Ξ˜ and π‘š :Ξ© →𝐺 such that

  1. (𝑒,𝑔),(𝑔,𝑒) ∈Ω and π‘š(𝑒,𝑔) =π‘š(𝑔,𝑒) =𝑔 for all 𝑔 ∈𝐺 (identity)
  2. if (𝑔,β„Ž),(β„Ž,𝑑),(π‘š(𝑔,β„Ž),𝑑),(𝑔,π‘š(β„Ž,𝑑)) ∈Ω then π‘š(π‘š(𝑔,β„Ž),𝑑) =π‘š(𝑔,(β„Ž,𝑑)) (associativity)
  3. (𝑔,𝑖(𝑔)),(𝑖(𝑔),𝑔) ∈Ω with π‘š(𝑔,𝑖(𝑔)) =π‘š(𝑖(𝑔),𝑔) =𝑒 for all 𝑔 ∈𝐺 (inverse)

Hence 𝐺 needn’t be closed under π‘š.


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