Embedding the boundary of the orbit space. M is a 3-manifold with rotational symmetry. A is a symmetry cell, i.e., the image of the orbit space N under a cross-section κ. The boundary ∂N consists of parts E and S whose points correspond to the points in ∂M and in the axis of rotation, respectively. iE and iS are the inclusion maps of E and S into N, and κE embeds E into ∂M.
Raumonen et al. Boundary Value Problems 2011 2011:9 doi:10.1186/1687-2770-2011-9