title: Kallman–Rota inequality
text: # Kallman–Rota inequality
  
  In mathematics, the Kallman–Rota inequality, introduced by Kallman & Rota (1970), is a generalization of the Landau–Kolmogorov inequality to Banach spaces. It states that if A is the infinitesimal generator of a one-parameter contraction semigroup then
  
      $\|Af\|^{2}\leq 4\|f\|\|A^{2}f\|.$
  