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Characterization of sets of determination for parabolic functions on a slab by coparabolic (minimal) thinness. (English) Zbl 0887.35064
A set $$M \subset \mathbb R^n \times ]0,T[$$ is said to be a set of determination, if $\inf u (\mathbb R^n\times ]0,T[)= \inf u (M)$ for every positive solution of the heat equation. In the paper (which complements the earlier article of the author [ibid. 35, 497-513 (1994; Zbl 0808.35043)], sets of determination are characterized in terms of parabolic limit points of $$M$$ as well as of (minimal) coparabolic thinness of various “thickenings” of $$M$$.
Reviewer: I.Netuka (Praha)
##### MSC:
 35K05 Heat equation 35B05 Oscillation, zeros of solutions, mean value theorems, etc. in context of PDEs
##### Keywords:
parabolic function; Harnack inequality
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