<p>In this paper, we study strong solutions and decay estimates for an incompressible Vlasov-magnetohydrodynamic (Vlasov-MHD) model arising in magnetized plasmas. This model consists of the Vlasov equation and the incompressible MHD equations, which interact mutually through the Lorentz force. It can be readily verified that the system has two equilibria: <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\((\bar{f},\bar{u},\bar{B})=(0,0,0)\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mover accent="true"> <mrow> <mi>f</mi> </mrow> <mrow> <mo stretchy="false">¯</mo> </mrow> </mover> <mo>,</mo> <mover accent="true"> <mrow> <mi>u</mi> </mrow> <mrow> <mo stretchy="false">¯</mo> </mrow> </mover> <mo>,</mo> <mover accent="true"> <mrow> <mi>B</mi> </mrow> <mrow> <mo stretchy="false">¯</mo> </mrow> </mover> <mo stretchy="false">)</mo> <mo>=</mo> <mo stretchy="false">(</mo> <mn>0</mn> <mo>,</mo> <mn>0</mn> <mo>,</mo> <mn>0</mn> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(( \tilde{f},\tilde{u},\tilde{B})=((2\pi )^{- \frac{3}{2}}e^{- \frac{|v|^2}{2}},0,0)\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mrow> <mo stretchy="false">(</mo> <mover accent="true"> <mi>f</mi> <mo stretchy="false">~</mo> </mover> <mo>,</mo> <mover accent="true"> <mi>u</mi> <mo stretchy="false">~</mo> </mover> <mo>,</mo> <mover accent="true"> <mi>B</mi> <mo stretchy="false">~</mo> </mover> <mo stretchy="false">)</mo> </mrow> <mo>=</mo> <mrow> <mo stretchy="false">(</mo> <msup> <mrow> <mo stretchy="false">(</mo> <mn>2</mn> <mi>π</mi> <mo stretchy="false">)</mo> </mrow> <mrow> <mo>-</mo> <mfrac> <mn>3</mn> <mn>2</mn> </mfrac> </mrow> </msup> <msup> <mi>e</mi> <mrow> <mo>-</mo> <mfrac> <msup> <mrow> <mo stretchy="false">|</mo> <mi>v</mi> <mo stretchy="false">|</mo> </mrow> <mn>2</mn> </msup> <mn>2</mn> </mfrac> </mrow> </msup> <mo>,</mo> <mn>0</mn> <mo>,</mo> <mn>0</mn> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation>. For any prescribed time interval, we establish the existence and uniqueness of strong solutions under appropriately small initial perturbations that depend on the length of the interval. In both the whole-space and periodic settings, we further derive the corresponding decay estimates for the fluid velocity and magnetic field over the interval of existence. The primary difficulty stems from the lack of drag-type or Fokker–Planck dissipation in the kinetic equation, along with the trilinear coupling generated by the Lorentz force. To address this issue, we combine the characteristic method, support propagation for the kinetic component, refined energy estimates, and Fourier analysis.</p>

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Strong solutions and decay estimates for the incompressible Vlasov-MHD system

  • Fucai Li,
  • Jinkai Ni,
  • Man Wu

摘要

In this paper, we study strong solutions and decay estimates for an incompressible Vlasov-magnetohydrodynamic (Vlasov-MHD) model arising in magnetized plasmas. This model consists of the Vlasov equation and the incompressible MHD equations, which interact mutually through the Lorentz force. It can be readily verified that the system has two equilibria: \((\bar{f},\bar{u},\bar{B})=(0,0,0)\) ( f ¯ , u ¯ , B ¯ ) = ( 0 , 0 , 0 ) and \(( \tilde{f},\tilde{u},\tilde{B})=((2\pi )^{- \frac{3}{2}}e^{- \frac{|v|^2}{2}},0,0)\) ( f ~ , u ~ , B ~ ) = ( ( 2 π ) - 3 2 e - | v | 2 2 , 0 , 0 ) . For any prescribed time interval, we establish the existence and uniqueness of strong solutions under appropriately small initial perturbations that depend on the length of the interval. In both the whole-space and periodic settings, we further derive the corresponding decay estimates for the fluid velocity and magnetic field over the interval of existence. The primary difficulty stems from the lack of drag-type or Fokker–Planck dissipation in the kinetic equation, along with the trilinear coupling generated by the Lorentz force. To address this issue, we combine the characteristic method, support propagation for the kinetic component, refined energy estimates, and Fourier analysis.