Displaying 101 – 120 of 251

Showing per page

Landau's theorem for p-harmonic mappings in several variables

Sh. Chen, S. Ponnusamy, X. Wang (2012)

Annales Polonici Mathematici

A 2p-times continuously differentiable complex-valued function f = u + iv in a domain D ⊆ ℂ is p-harmonic if f satisfies the p-harmonic equation Δ p f = 0 , where p (≥ 1) is a positive integer and Δ represents the complex Laplacian operator. If Ω ⊂ ℂⁿ is a domain, then a function f : Ω m is said to be p-harmonic in Ω if each component function f i (i∈ 1,...,m) of f = ( f , . . . , f m ) is p-harmonic with respect to each variable separately. In this paper, we prove Landau and Bloch’s theorem for a class of p-harmonic mappings f from...

Liouville type theorems for φ-subharmonic functions.

Marco Rigoli, Alberto G. Setti (2001)

Revista Matemática Iberoamericana

In this paper we present some Liouville type theorems for solutions of differential inequalities involving the φ-Laplacian. Our results, in particular, improve and generalize known results for the Laplacian and the p-Laplacian, and are new even in these cases. Phragmen-Lindeloff type results, and a weak form of the Omori-Yau maximum principle are also discussed.

Majorantes surharmoniques minimales d'une fonction continue

Jean-Jacques Moreau (1971)

Annales de l'institut Fourier

Soit Ω , ouvert de R n et f : Ω R , continue. On dit qu’une majorante surharmonique de f dans Ω est minimale si cette majorante surharmonique est harmonique dans l’ensemble (ouvert) où elle diffère de f . Beaucoup de propriétés de ces fonctions sont semblables à celles des fonctions harmoniques 0 (lesquelles correspondent à f = 0 ) ; par exemple la famille entière est uniformément équicontinue dans chaque partie compacte de Ω , relativement à la structure uniforme de R . On traite le problème de Dirichlet : détermination...

Maximal Weak-Type Inequality for Orthogonal Harmonic Functions and Martingales

Adam Osękowski (2013)

Bulletin of the Polish Academy of Sciences. Mathematics

Assume that u, v are conjugate harmonic functions on the unit disc of ℂ, normalized so that u(0) = v(0) = 0. Let u*, |v|* stand for the one- and two-sided Brownian maxima of u and v, respectively. The paper contains the proof of the sharp weak-type estimate ℙ(|v|* ≥ 1)≤ (1 + 1/3² + 1/5² + 1/7² + ...)/(1 - 1/3² + 1/5² - 1/7² + ...) 𝔼u*. Actually, this estimate is shown to be true in the more general setting of differentially subordinate harmonic functions defined...

Mean value densities for temperatures

N. Suzuki, N. A. Watson (2003)

Colloquium Mathematicae

A positive measurable function K on a domain D in n + 1 is called a mean value density for temperatures if u ( 0 , 0 ) = D K ( x , t ) u ( x , t ) d x d t for all temperatures u on D̅. We construct such a density for some domains. The existence of a bounded density and a density which is bounded away from zero on D is also discussed.

Currently displaying 101 – 120 of 251