Operators on Complex Vector Spaces — Sheldon Axler
Mathematics — Linear Algebra · nilpotent-operators
Problem
Give an example of an operator T on a finite-dimensional real vector space such that 0 is the only eigenvalue of T but T is not nilpotent.
This exercise shows that the implication (b) ⇒ (a) in 8.17 does not hold without the hypothesis that F=C.