© HaiyuWen 2009
Received: 10 March 2009
Accepted: 18 May 2009
Published: 16 June 2009
In the recent years, the -harmonic equations for differential forms have been widely investigated, see , and many interesting and important results have been found, such as some weighted integral inequalities for solutions to the -harmonic equations; see [2–7]. Those results are important for studying the theory of differential forms and both qualitative and quantitative properties of the solutions to the different versions of -harmonic equation. In the different versions of -harmonic equation, the nonhomogeneous -harmonic equation has received increasing attentions, in  Ding has presented some estimates to such equation. In this paper, we extend some estimates that Ding has presented in  into the two-weight case. Our results are more general, so they can be used broadly.
It is well-known that the Lipschitz norm , where the supremum is over all local cubes , as is the BMO norm , so the natural limit of the space locLipk( ) as is the space BMO( ). In Section 3, we establish a relation between these two norms and -norm. We first present the local two-weight Poincaré inequality for -harmonic tensors. Then, as the application of this inequality and the result in , we prove some weighted Lipschitz norm inequalities and BMO norm inequalities for differential forms satisfying the different nonhomogeneous -harmonic equations. These results can be used to study the basic properties of the solutions to the nonhomogeneous -harmonic equations.
Now, we first introduce related concepts and notations.
Throughout this paper we assume that is a bounded connected open subset of . We assume that is a ball in with diameter and is the ball with the same center as with . We use to denote the Lebesgue measure of . We denote a weight if and a.e.. Also in general . For , we write if the weighted -norm of over satisfies , where is a real number. A differential -form on is a schwartz distribution on with value in , we denote the space of differential -forms by . We write for the -forms with for all ordered -tuples , , . Thus is a Banach space with norm . We denote the exterior derivative by for . Its formal adjoint operator is given by on , . A differential -form is called a closed form if in . Similarly, a differential -form is called a coclosed form if . The -form is defined by , and , , for all , , here is a homotopy operator, for its definition, see .
We call an -harmonic tensor in if satisfies the -harmonic equation (1.4) in .
In this section, we will extend Lemma 2.3, see in , to new version with weight both locally and globally.
See  for properties of -weights. We will need the following generalized Hölder's inequality.
We also need the following lemma; see .
The proof of Theorem 2.4 has been completed.
As applications of the local results, we prove the following global norm comparison theorem.
We see that -weight reduce to the usual -weight if and ; see .
And, if and in Theorem 2.7, it is easy to obtain Theorems and in .
3. Estimates for Lipschitz Norms and BMO Norms
In  Ding has presented some estimates for the Lipchitz norms and BMO norms. In this section, we will prove another estimates for the Lipchitz norms and BMO norms.
We also discuss the weighted Lipschitz and BMO norms.
We need the following classical Poincaré inequality; see .
We also need the following lemma; see .
This ends the proof of Theorem 3.5.
Similarly, if setting and in Theorem 3.5, we obtain Theorem in . And we choose in Theorem 3.5, we have the classical Poincaré inequality (3.5).
Lemma 3.6 (see ).
Now, we have completed the proof of Theorem 3.7.
Using Lemma 3.6, we can also obtain the following theorem.
This work was supported by Science Research Foundation in Harbin Institute of Technology (HITC200709) and Development Program for Outstanding Young Teachers in HIT (HITQNJS.2006.052).
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