Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity
    
    
  
  
  
      
      
      
        
Teoretičeskaâ i matematičeskaâ fizika, Tome 215 (2023) no. 2, pp. 318-335
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			We use asymptotic analysis to study the existence of solutions of a one-dimensional nonlinear system of ordinary differential equations with different powers of a small parameter at higher derivatives. A specific feature of the problem is the presence of a discontinuity of the first kind in the right-hand side of the equation $\varepsilon^4u''=f(u,v,x,\varepsilon)$ in the unknown variable $u$ at the level $u=0$, while the right-hand side of the second equation $\varepsilon^2v''=g(u,v,x,\varepsilon)$ is assumed to be smooth in all variables. We define a generalized solution of the problem is in terms of differential inclusions. Conditions under which generalized solutions turn into strong ones are proposed, and the possibility that the $u$-component of the solution intersects zero only once is studied. The existence theorems are proved by using the asymptotic method of differential inequalities.
			
            
            
            
          
        
      
                  
                    
                    
                    
                    
                    
                      
Keywords: 
system of nonlinear equations, small parameter, internal layer, upper and lower solutions, solution asymptotics, strong solutions, discontinuity of the first kind.
                    
                  
                
                
                @article{TMF_2023_215_2_a11,
     author = {B. V. Tischenko},
     title = {Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {318--335},
     publisher = {mathdoc},
     volume = {215},
     number = {2},
     year = {2023},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2023_215_2_a11/}
}
                      
                      
                    TY - JOUR AU - B. V. Tischenko TI - Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity JO - Teoretičeskaâ i matematičeskaâ fizika PY - 2023 SP - 318 EP - 335 VL - 215 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TMF_2023_215_2_a11/ LA - ru ID - TMF_2023_215_2_a11 ER -
%0 Journal Article %A B. V. Tischenko %T Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity %J Teoretičeskaâ i matematičeskaâ fizika %D 2023 %P 318-335 %V 215 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2023_215_2_a11/ %G ru %F TMF_2023_215_2_a11
B. V. Tischenko. Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity. Teoretičeskaâ i matematičeskaâ fizika, Tome 215 (2023) no. 2, pp. 318-335. http://geodesic.mathdoc.fr/item/TMF_2023_215_2_a11/
