This is a preview of subscription content, log in via an institution to check access.
Literature Cited
A. Yanushauskas, “On the zeros of the gradient of an harmonic function,” Dokl. Akad. Nauk SSSR,158, No. 3, 547–549 (1964).
M. A. Krasnosel'skii, Plane Vector Fields, London (1966).
S. Lefschetz, Differential Equations: Geometric Theory, Interscience, New York (1963).
H. Cartan and F. Bruhat, “Sur les composantes irréductibles d'un susensemble analitique-réel,” Comptes Rendus,244, 988, 1123–1126 (1957).
M. A. Krasnosel'skii, The Operator of Translation along the Trajectories of Differential Equations, Providence, R. I. (1958).
Additional information
Translated from Sibirskii Matematicheskii Zhurnal, Vol. 10, No. 3, pp. 685–691, May–June, 1969.
Rights and permissions
About this article
Cite this article
Yanushauskas, A. The zeros of the gradient and the Hessian of an harmonic function. Sib Math J 10, 497–501 (1969). https://doi.org/10.1007/BF01078339
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01078339