Published online by Cambridge University Press: 20 January 2009
Let be a linear differential expression involving n independent variables xi the coefficients Aik Bi, and C being functions of the independent variables but not involving the dependent variable u. Associated with F(u) is the adjoint expression
* See Courant u. Hilbert: Methoden der Mathematischen Physik. Band I., Kap. IV., §8.
† E.g. in Dynamics, the theorems of conservation of energy and momentum. See a paper by Noether, Emmy: Gött. Nach. (1918), p. 238.Google Scholar Also the present author's paper Proc. Edin. Math. Soc., 42, p 61.CrossRefGoogle Scholar