Displaying similar documents to “Harnack's inequality for solutions of some degenerate elliptic equations.”

Mapping properties of the elliptic maximal function.

M. Burak Erdogan (2003)

Revista Matemática Iberoamericana

Similarity:

We prove that the elliptic maximal function maps the Sobolev space W4,eta(R2) into L4(R2) for all eta > 1/6. The main ingredients of the proof are an analysis of the intersectiQn properties of elliptic annuli and a combinatorial method of Kolasa and Wolff.

The existence of positive solution to some asymptotically linear elliptic equations in exterior domains.

Gongbao Li, Gao-Feng Zheng (2006)

Revista Matemática Iberoamericana

Similarity:

In this paper, we are concerned with the asymptotically linear elliptic problem -Δu + λu = f(u), u ∈ H (Ω) in an exterior domain Ω = RO (N ≥ 3) with O a smooth bounded and star-shaped open set, and lim f(t)/t = l, 0 < l < +∞. Using a precise deformation lemma and algebraic topology argument, we prove under our assumptions that the problem possesses at least one positive solution.

Time-frequency analysis of Sjöstrand's class.

Karlheinz Gröchenig (2006)

Revista Matemática Iberoamericana

Similarity:

We investigate the properties an exotic symbol class of pseudodifferential operators, Sjöstrand's class, with methods of time-frequency analysis (phase space analysis). Compared to the classical treatment, the time-frequency approach leads to striklingly simple proofs of Sjöstrand's fundamental results and to far-reaching generalizations.

Multi-parameter paraproducts.

Camil Muscalu, Jill Pipher, Terence Tao, Christoph Thiele (2006)

Revista Matemática Iberoamericana

Similarity:

We prove that classical Coifman-Meyer theorem holds on any polidisc T or arbitrary dimension d ≥ 1.

SAK principle for a class of Grushin-type operators.

Lidia Maniccia, Marco Mughetti (2006)

Revista Matemática Iberoamericana

Similarity:

We prove Fefferman's SAK Principle for a class of hypoelliptic operators on R whose nonnegative symbol vanishes anisotropically on the characteristic manifold.