Article        
                          
                  
                         
      
  
  
     Ufa Mathematical Journal
 Volume 8, Number 3, pp. 79-94
Asymptotics for the eigenvalues of a fourth order differential operator  in a "degenerate" case
Ishkin Kh.K., Murtazin Kh.Kh.
DOI:10.13108/2016-8-3-79
Download PDF
 Article on MathNetAbstact
In the paper we consider operator $L$ in $L^{2}[0,+\infty)$ 
generated by the differential expression
$\mathcal{L}(y)=y^{(4)}-2(p(x)y')'+q(x)y$ and boundary conditions  $ y(0)=y''(0)=0$ in the  ``degenerate'' case, when the roots of associated characteristic equation has different growth rate at the infinity. Assuming a power growth for functions $p$ and $q$ under some additional conditions of smoothness and regularity kind, we obtain an asymptotic equation for the spectrum allowing us to write out several first terms in the asymptotic expansion for the eigenvalues of operator $L$.