arXiv subjects
Publications and source records attributed to D. Q. Khai.
In this paper, we prove some results on the existence and decay properties of high order derivatives in time and space variables for local and global solutions of the Cauchy problem for the Navier-Stokes equations in Sobolev.
In this paper, we study local well-posedness for the Navier-Stokes \linebreak equations with arbitrary initial data in homogeneous Sobolev spaces $\dot{H}^s_p(\mathbb{R}^d)$ for $d \geq 2, p > \frac{d}{2},\ {\rm and}\ \frac{d}{p} - 1 \leq s < \frac{d}{2p}$. The obtained result improves the known ones for $p > d$ and $s = 0$ M. Cannone and Y. Meyer (1995). In the case of critical indexes $s=\frac{d}{p}-1$, we prove global well-posedness for Navier-Stokes equations when the norm of the initial value is small enough. This result is a generalization of the one in M. Cannone (1997) in which $p = d$ and $s = 0$.
In this paper, we study local well-posedness for the Navier-Stokes equations with arbitrary initial data in homogeneous Sobolev spaces $\dot{H}^s_p(\mathbb{R}^d)$ for $d \geq 2, p > \frac{d}{2},\ {\rm and}\ \frac{d}{p} - 1 \leq s < \frac{d}{2p}$. The obtained result improves the known ones for $p > d$ and $s = 0$ (see M. Cannone (1995), M. Cannone and Y. Meyer (1995)). In the case of critical indexes $s=\frac{d}{p}-1$, we prove global well-posedness for Navier-Stokes equations when the norm of the initial value is small enough. This result is a generalization of the ones in Cannone (1999) and P. G. Lemarie-Rieusset (2002) in which $(p = d, s = 0)$ and $(p > d, s = \frac{d}{p} - 1)$, respectively.
In this paper, we study local well-posedness for the Navier-Stokes equations (NSE) with the arbitrary initial value in homogeneous Sobolev-Lorentz spaces $\dot{H}^s_{L^{q, r}}(\mathbb{R}^d):= (-Δ)^{-s/2}L^{q,r}$ for $d \geq 2, q > 1, s \geq 0$, $1 \leq r \leq \infty$, and $ \frac{d}{q}-1 \leq s < \frac{d}{q}$, this result improves the known results for $q > d,r=q, s = 0$ (see M. Cannone (1995) and M. Cannone and Y. Meyer (1995)) and for $q =r= 2, \frac{d}{2} - 1 < s < \frac{d}{2}$ (see M. Cannone (1995, J. M. Chemin (1992)). In the case of critical indexes ($s=\frac{d}{q}-1$), we prove global well-posedness for NSE provided the norm of the initial value is small enough. The result that is a generalization of the result of M. Cannone (1997) for $q = r=d, s=0$.
In this paper, we prove some results on theexistence and space-time decay rates of global strong solutions of the Cauchy problem for the Navier-Stokes equations in weighed $L^\infty(\mathbb R^d,|x|^γ{\rm dx})\cap L^\infty(\mathbb R^d,|x|^β{\rm dx})$ spaces.
The existence of local unique mild solutions to the Navier-Stokes equations in the whole space with an initial tempered distribution datum in critical homogeneous or inhomogeneous Sobolev spaces is shown. Especially, the case when the integral-exponent is less than 2 is investigated. The global existence is also obtained for the initial datum in critical homogeneous Sobolev spaces with a norm small enough in suitable critical Besov spaces. The key lemma is to establish the bilinear estimates in these spaces, due to the point-wise decay of the kernel of the heat semigroup.
In this note, for $s \in \mathbb R$ and $1 \leq p, r \leq \infty$, we introduce and study Sobolev-Fourier-Lorentz spaces $\dot{H}^s_{\mathcal{L}^{p, r}}(\mathbb{R}^d)$. In the family spaces $\dot{H}^s_{\mathcal{L}^{p, r}}(\mathbb{R}^d)$, the critical invariant spaces for the Navier-Stokes equations correspond to the value $s = \frac{d}{p} - 1$. When the initial datum belongs to the critical spaces $\dot{H}^{\frac{d}{p} - 1}_{\mathcal{L}^{p,r}}(\mathbb{R}^d)$ with $d \geq 2, 1 \leq p <\infty$, and $1 \leq r < \infty$, we establish the existence of local mild solutions to the Cauchy problem for the Navier-Stokes equations in spaces $L^\infty([0, T]; \dot{H}^{\frac{d}{p} - 1}_{\mathcal{L}^{p, r}}(\mathbb{R}^d))$ with arbitrary initial value, and existence of global mild solutions in spaces $L^\infty([0, \infty); \dot{H}^{\frac{d}{p} - 1}_{\mathcal{L}^{p, r}}(\mathbb{R}^d))$ when the norm of the initial value in the Besov spaces $\dot{B}^{\frac{d}{\tilde p} - 1, \infty}_{\mathcal{L} ^{\tilde p,\infty}}(\mathbb{R}^d)$ is small enough, where $\tilde p$ may take some suitable values.