Necessary and sufficient conditions of harmonicity of functions of infinitely many variables (Jacobian case)
Abstract
A criterion of harmonicity of functions in a Hilbert space is given in the case of weakened mutual dependence of the second derivatives.
English version (Springer): Ukrainian Mathematical Journal 46 (1994), no. 6, pp 857-862.
Citation Example: Feller M. N. Necessary and sufficient conditions of harmonicity of functions of infinitely many variables (Jacobian case) // Ukr. Mat. Zh. - 1994. - 46, № 6. - pp. 785–788.
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