On the negative spectrum of an elliptic operator
    
    
  
  
  
      
      
      
        
Sbornik. Mathematics, Tome 69 (1991) no. 1, pp. 155-177
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			New estimates are given for the number of points in the negative spectrum for an elliptic operator or arbitrary order. These estimates generalize and refine the well-known results of Rozenblyum, Lieb, Cwikel, the authors, and others. The proofs have a simple geometric character, and are based on uncomplicated dimensionless imbedding theorems. Also given are results for degenerate elliptic operators, for operators in a domain that contracts or expands in a definite way at infinity, and so on. Theorem 10 gives conditions under which the essential spectrum of an operator contains infinitely many points.
			
            
            
            
          
        
      @article{SM_1991_69_1_a9,
     author = {Yu. V. Egorov and V. A. Kondrat'ev},
     title = {On the negative spectrum of an elliptic operator},
     journal = {Sbornik. Mathematics},
     pages = {155--177},
     publisher = {mathdoc},
     volume = {69},
     number = {1},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_69_1_a9/}
}
                      
                      
                    Yu. V. Egorov; V. A. Kondrat'ev. On the negative spectrum of an elliptic operator. Sbornik. Mathematics, Tome 69 (1991) no. 1, pp. 155-177. http://geodesic.mathdoc.fr/item/SM_1991_69_1_a9/
