A bound on the nucleon Druck-term from chiral EFT in curved space-time and mechanical stability conditions

Using dispersive representations of the nucleon gravitational form factors, results for their absorptive parts from chiral effective field theory in curved space-time, and mechanical stability conditions, we obtain a model independent inequality value $D(t)$ factor at zero momentum transfer (Druck-term). In particular, obtained leads to conservative bound on Druck-term limit $D \leq -0.95(9)$. This implies restriction low-energy constant $c_8$ action nucleons pions presence an external field, $c_8\leq -1.1(1)$ GeV$^{-1}$. For physical pion mass $D\leq -0.20(2)$.