Current-Algebra, Subtracted Dispersion Relation, andKl3form Factors

A calculation of the $K_{l3\mathrm{}}$ form factors is done on the basis of current algebra, partial conservation of axial-vector currents (strangeness conserving), and dispersion relations. Assuming once-subtracted and unsubtracted dispersion relations for $f_{+}\left(q^2\right)+f_{-}\left(q^2\right)$ and $f_{+}\left(q^2\right)-f_{-}\left(q^2\right)$, respectively, and $K^{*}$ dominance, the $K_{l3\mathrm{}}$ decay parameters $\xi$, ${\lambda }_{+}$, and ${\lambda }_{-}$ are calculated. All results are consistent with the present experimental indications.