MODIFIED DISPERSION RELATIONS AND SUM RULES

A systematic treatment of modifications to the usual form of dispersion relations and sum rules is given. The treatment is based on the fact that if a function g(z) has analyticity properties analogous to those of a scattering amplitude f (z), the usual dispersion relation for the product f (z)g(z) holds. After having described the general form of the weight function" g(z) we concentrate on cases when g(z) is large in a pre-chosen region and small elsewhere. Weight functions of this type are useful in practical applications where a weight function g(z) may enhance a contribution of regions where accurate data are available and suppress those of regions with inaccurate or lacking data. © 1969 Czechoslovak Academy of Sciences."