Zeros of $varsigma " (s)$ and $varsigma ''' (s)$ in $/sigma$ < 1/2

Abstract

There is only one pair of non-real zeros of $varsigma " (s)$, and of $varsigma ''' (s)$, in the left half-plane. The Riemann Hypothesis implies that $varsigma " (s)$ and $varsigma ''' (s)$ have no zeros in the strip 0 leq Re,s < {1over 2} .