In geometry and topology, given a group G (which may be a topological or Lie group), an equivariant bundle is a fiber bundle
π
:
E
→
B
{\displaystyle \pi \colon E\to B}
such that the total space
E
{\displaystyle E}
and the base space
B
{\displaystyle B}
are both G-spaces (continuous or smooth, depending on the setting) and the projection map
π
{\displaystyle \pi }
between them is equivariant:
π
∘
g
=
g
∘
π
{\displaystyle \pi \circ g=g\circ \pi }
with some extra requirement depending on a typical fiber.
For example, an equivariant vector bundle is an equivariant bundle such that the action of G restricts to a linear isomorphism between fibres.
References
- Berline, Nicole; Getzler, E.; Vergne, Michèle (2004), Heat Kernels and Dirac Operators, Berlin, New York: Springer-Verlag