根据YIN和WANG的方法,结合Fichera-Oleinik理论,研究奇异扩散方程:φ( u)/t =div(ραu p-2u),(x,t)∈QT =Ωx(0,T),其中Ω是RN 中的有界区域,边界Ω充分光滑,ρ(x)=dist(x,Ω), p 〉1,α〉0,φ满足:φ∈C2,且存在δ〉0使得φ′(s)〉δ〉0.证明了α≥p -1时,不需要任何边值条件,方程最多有一个满足初值条件的解;而0〈α〈 p -1时,方程存在唯一满足初边值条件弱解.
The paper studies the singular diffusion equation in the method of YIN ’s and WANG ’s with Fichera-Oleinik theory:φ(u)/t = div(ρα u p-2 u),(x,t)∈QT = Ωx (0,T), whereΩis a bounded domain in RN with appropriately smooth boundaryΩ,ρ(x) = dist(x,Ω) , p 〉 1,α 〉 0 ,φ∈C2 , and there existsδ 〉0 such thatφ′( s) 〉 δ 〉0 . The paper proves that ifα≥p-1 , the equation admits a unique solution subject only to a given initial condition without any boundary condition, while if 0 〈 α 〈 p -1 , for a given initial condition, the equation admits different solutions for different boundary conditions.