The exixtence of generalized solutions for a class of linear and nonlinear equations of mixed type


Abstract


In this paper we deal with the question of existence and uniqueness of the generalized solutions for a class of linear and nonlinear equations of the mixed type. In particular we consider L(u)≡  k(y) u_{xx} + u_{yy} = f (x,y,u) in a simply connected region G , where k(y)≥ 0 for y≥ 0 and k(y)< 0 for y < 0. G is bounded by the curves Γ0120 is a piecewise smooth curve lying in the half plane y > 0 which intersects the line y= 0 at the points P(- 1,0) , Q(0,0); Γ1 is a piecewise smooth curve through P in y < (Error rendering LaTeX formula)Γ2(Error rendering LaTeX formula)Γ1$ either lies in the characteristic triangle formed by the characteristics through P and Q (Frankl Problem) or coincides with the characteristics through P (Tricomi Problem). We seek sufficient conditions for the existence and uniqueness of generalized solutions of the boundary problem (Error rendering LaTeX formula)

DOI Code: 10.1285/i15900932v10supn1p47

Keywords: Linear; Nonlinear; Tricomi-Frankl problem

Classification: 35D05; 35M05

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