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4 votes
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103 views

Characteristic of Sobolev space generated by Hörmander vector fields

Let $\Omega$ be an open bounded domain in $\mathbb{R}^{n}$ with smooth boundary $\partial\Omega$. Suppose that $X=(X_{1},X_{2},\ldots,X_{m})$ are smooth vector fields defined on $\mathbb{R}^{n}$ and ...
pxchg1200's user avatar
  • 287
3 votes
0 answers
56 views

Regularity of subelliptic eigenfunction on characteristic domain

Background: Consider the Hörmander vector fields $X=(X_1,\cdots,X_m)$ on $\mathbb{R}^n$, and the associated Dirichlet eigenvalue problem $$-\Delta u:=\sum_{i=1}^mX_i^*X_iu=\lambda u~~\text{on}~\Omega,~...
Houa's user avatar
  • 561
3 votes
0 answers
143 views

Homogeneous Carnot group, its Lie algebra and Carnot-Carathéodory ball

Background: Let the smooth vector fields $X=(X_1,\cdots,X_m)$ define on $\mathbb{R}^n$ and they satisfy the following assumption: (H1): There is a dilation structure $$\delta_{t}:\mathbb{R}^n\to \...
Houa's user avatar
  • 561
3 votes
1 answer
606 views

how to use the sobolev inequality to obtain the embedding theorem

I am reading Luca Capogna's article An Embedding theorem and the Harnack inequalitiy for nonlinear subelliptic equations. In this article, the authors proved the following theorem (Theorem 2.3) Let ...
pxchg1200's user avatar
  • 287
2 votes
1 answer
292 views

The relationship about sub-unit ball and sub-elliptic ball

Let $\Omega$ be a bounded open domain in $\mathbb{R}^{n}$ with smooth boundary.$\{X_{1},\cdots,X_{m}\}$ be smooth real vector fields on $\Omega$ Which satisfy the Hormander condition. If $\gamma$ is ...
pxchg1200's user avatar
  • 287
4 votes
1 answer
234 views

dirichlet problem in the heisenberg group

Good morning everybody. I was looking just for a quick reference to know whether the Dirichlet problem has a solution in the Heisenberg group, that is $\mathbb R^3$ endowed with coordinates $(x,y,z)$ ...
guido giuliani's user avatar
2 votes
2 answers
442 views

Principal bundles and Subriemannian Geometry

In sub-Riemannian geometry, one considers manifolds $P$ equipped with a subbundle $\mathcal{H}$ of $TP$, the horizontal distribution. One then has a Riemannian metric only on this distribution $\...
Matthias Ludewig's user avatar