A spectrahedronspectrahedron is a convex set defined by a linear matrix inequality (https://en.wikipedia.org/wiki/SpectrahedronLMI).
I was wondering ifIs the boundary of such a set is almost always smooth.?
By "smooth" I mean that it admits a tangent hyperplane at any point of the surface.
I say "almost" because, for the special case of the polytope, the boundary has many "edges", so the answer in. In this special case, the answer would be no.