The Riemann Extensions in Theory of Ordinary Differential Equations and their Applications

Valery S. Dryuma

Some properties of the 4-dim Riemannian spaces with the metrics $$d{s}^2=2(z{a}_3-t{a}_4)d{x}^2+4(z{a}_2-t{a}_3)dxdy+2(z{a}_1-t{a}_2)d{y}^2+2dxdz+2dydt$$ associated with the second order nonlinear…