Criteria for the existence of periodic and bounded solutions of three-dimensional systems of differential equations
    
    
  
  
  
      
      
      
        
Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 27 (2021) no. 1, pp. 157-172
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			We study necessary and sufficient conditions for the existence of periodic and bounded solutions for one class of three-dimensional systems of nonlinear ordinary differential equations. The main nonlinear positively homogeneous terms are distinguished in the systems under consideration. Criteria for the existence of periodic and bounded solutions are formulated in terms of the properties of main nonlinear terms. For the periodic problem, it is proved that the previously known sufficient condition for the existence of periodic solutions is also a necessary condition. In the question of the existence of bounded solutions, it is proved that under a homotopy of the main nonlinear terms, the property of the existence of bounded solutions is preserved. Based on this, a new criterion for the existence of bounded solutions is proved with the use of methods of the qualitative theory of differential equations and nonlinear analysis, including the method of guiding functions and the topological method of Vazhevsky. The obtained results can be further generalized for multidimensional systems of differential equations.
			
            
            
            
          
        
      
                  
                    
                    
                    
                    
                    
                      
Keywords: 
three-dimensional system of nonlinear ordinary differential equations, periodic solution, bounded solution, method of guiding functions, rotation of a vector field, Vazhevsky topological method.
Mots-clés : homotopy relation
                    
                  
                
                
                Mots-clés : homotopy relation
@article{TIMM_2021_27_1_a15,
     author = {\`E. M. Muhamadiev and A. N. Naimov},
     title = {Criteria for the existence of periodic and bounded solutions of three-dimensional systems of differential equations},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {157--172},
     publisher = {mathdoc},
     volume = {27},
     number = {1},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2021_27_1_a15/}
}
                      
                      
                    TY - JOUR AU - È. M. Muhamadiev AU - A. N. Naimov TI - Criteria for the existence of periodic and bounded solutions of three-dimensional systems of differential equations JO - Trudy Instituta matematiki i mehaniki PY - 2021 SP - 157 EP - 172 VL - 27 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TIMM_2021_27_1_a15/ LA - ru ID - TIMM_2021_27_1_a15 ER -
%0 Journal Article %A È. M. Muhamadiev %A A. N. Naimov %T Criteria for the existence of periodic and bounded solutions of three-dimensional systems of differential equations %J Trudy Instituta matematiki i mehaniki %D 2021 %P 157-172 %V 27 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/TIMM_2021_27_1_a15/ %G ru %F TIMM_2021_27_1_a15
È. M. Muhamadiev; A. N. Naimov. Criteria for the existence of periodic and bounded solutions of three-dimensional systems of differential equations. Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 27 (2021) no. 1, pp. 157-172. http://geodesic.mathdoc.fr/item/TIMM_2021_27_1_a15/
