Displaying similar documents to “Perturbation and energy estimates”

When is a pseudo-differential equation solvable ?

Nicolas Lerner (2000)

Annales de l'institut Fourier

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This paper begins with a broad survey of the state of the art in matters of solvability for differential and pseudo-differential equations. Then we proceed with a Hilbertian lemma which we use to prove a new solvability result.

Fefferman's SAK principle in one dimension

Frédéric Hérau (2000)

Annales de l'institut Fourier

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In this article we give a complete proof in one dimension of an a priori inequality involving pseudo-differential operators: if a and b are symbols in S 1 , 0 2 such that | a | b , then for all ϵ > 0 we have the estimate a w u s 2 C ϵ ( b w u s 2 + u s + ϵ 2 ) for all u in the Schwartz space, where t is the usual H t norm. We use microlocalization of levels I, II and III in the spirit of Fefferman’s SAK principle.