Comment on the Criticism of the One-Dimensional Solution of the K13Elastic Problem in Nematics

On the basis of a simple one-dimensional theoretical analysis made in the frame of the Euler-Lagrange formalism it is shown that the K13 elastic problem is a purely nonlinear elastic problem. This result completely invalidates the criticism of the one-dimensional solution of the K13 elastic problem in nematics based on linear functions and constants. It is found the magnitude and the sign of the second-order elastic constant K13 and it is shown that the Frank elastic constants of splay K13 and bend K33 must be positive. These results clearly show that the KI3 elastic problem can be successfully resolved only in the frame of the Euler-Lagrange formalism and that the elastic theory of Nehring and Saupe for the case of the nematics has been obtained under correct assumptions.