Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Three identical (truncated) ellipsoids in with different orientations. The two leftmost ellipsoids can be carried over to each other through a rotation around the (vertical in the figure) z-axis, which implies that they represent the same tensor Rabcd (up to the meaning discussed). The right ellipsoid, despite identical eigenvalues with the two others, represent a different tensor since the rotation which carries this ellipsoid to any of the others is not around the z-axis
