Fibre bundle

Bundle section

Consider a fibre bundle.

πΉβ†’πΈπœ‹β† π΅.

A section of the bundle is simply a section of πœ‹ in the sense of category theory, top i.e. a morphism 𝜎 :𝐡 β†ͺ𝐸 such that πœ‹πœŽ =1𝐡.

This makes a section a special case of a bundle map if we consider 𝐡 as a bundle over itself, so the set of all sections is given by

Ξ“(𝐡,𝐸)=Γ𝐸:=π–‘π—Žπ—‡π–½π΅(𝐸,𝐡)

A section can be thought of as a dependently typed function, sending each 𝑝 ∈𝐡 to a 𝜎(𝑝) in the fibre 𝐸𝑝.


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