Analyticity and Regge asymptotics in virtual Compton scattering on the nucleon

We test the consistency of data on nucleon structure functions with analyticity and Regge asymptotics virtual Compton amplitude. By solving a functional extremal problem, we derive an optimal lower bound maximum difference between exact amplitude dominant Reggeon contribution for energies $\nu$ above certain high value $\nu_h(Q^2)$. Considering in particular amplitudes $T_1^\inel(\nu, Q^2)$ proton neutron, find that decreases impressive way when $\nu_h(Q^2)$ is increased, represents very small fraction magnitude Reggeon. While method cannot rule out hypothesis fixed pole, results indicate function are consistent asymptotic behaviour given by leading contributions. also show minimum as subtraction constant $S_1^\inel(Q^2)$ provides reasonable estimate this quantity, frame similar, but not identical to dominance hypothesis.