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Petrovsky lacuna
From Wikipedia, the free encyclopedia
In mathematics, a Petrovsky lacuna, named for the Russian mathematician I. G. Petrovsky, is a region where the fundamental solution of a linear hyperbolic partial differential equation vanishes. They were studied by Petrovsky (1945) who found topological conditions for their existence.
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For other uses, see Lacuna.
Petrovsky's work was generalized and updated by Atiyah, Bott, and Gårding (1970, 1973).