Quasigraded Lie Algebras and Modified Toda Field Equations

We construct a family of quasigraded Lie algebras that coincide with the deformations of the loop algebras in “principal” gradation and admit Kostant–Adler–Symes scheme. Using them we obtain new Volterra coupled systems and modified Toda field equations for all series of classical matrix Lie algebras $\mathfrak g$.