[Math] Why left eigenvector complex conjugate transpose of right eigenvector

complex numberseigenvalues-eigenvectorsmatrices

My teacher today stated the following:
For a matrix $A\in \Bbb R^{n \times n}$, any left eigenvalue $e^*$ is simply the transpose of the conjugate of a right eigenvector $e$ of $A$, so $e^* = \overline e^T$.
I can't figure out why this should be the case for any real matrix $A$, only for symmetric matrices. Can anyone explain why this is?

Best Answer

It is not true in general.

Take $A=\begin{bmatrix} 1 & 1 \\ 0 & 0 \end{bmatrix}$, then with $v^*=(1,1)$ we have $v^* A = v^* $, but $A v = (2,0)^T \neq v$.