On the similarity of Sturm-Liouville operators with non-Hermitian boundary conditions to self-adjoint and normal operators
GFM seminar
	    
	      IIIUL, B2-01
	    
	    
                        
                        
                            2012-02-24 14:00
                            2012-02-24 15:00
                            2012-02-24
                            14:00
                            ..
                            15:00
                        
            
	    
            
	    
        by Petr Siegl (GFMUL, Portugal)
            We  consider one-dimensional Schroedinger-type operators in a bounded  interval with non-self-adjoint Robin-type boundary conditions. It is  well known that such operators are generically conjugate to normal  operators via a similarity transformation. Motivated  by recent interests in quasi-Hermitian Hamiltonians in quantum  mechanics, we study properties of the transformations in detail. We show  that they can be expressed as the sum of the identity and an integral  Hilbert-Schmidt operator. In the case of parity and  time reversal boundary conditions, we establish closed integral-type  formulae for the similarity transformations, derive the similar  self-adjoint operator and also find the associated “charge conjugation”  operator, which plays the role of fundamental symmetry  in a Krein space reformulation of the problem. 
Further generalisations to operators in two dimensional manifolds will be mentioned.
The talk is based on joint works with D. Krejcirik (NPI ASCR, Rez) and J. Zelezny} (FZU ASCR, Prague):
[1] D. Krejcirik, P. Siegl and J. Zelezny: On the similarity of Sturm-Liouville operators with non-Hermitian boundary conditions to self-adjoint and normal operators, preprint available at arXiv:1108.4946;
[2] D. Krejcirik and P. Siegl: PT-symmetric models in curved manifolds}, Journal of Physics A: Mathematical and Theoretical, 43 (2010), 485204 (30pp).
        
        Further generalisations to operators in two dimensional manifolds will be mentioned.
The talk is based on joint works with D. Krejcirik (NPI ASCR, Rez) and J. Zelezny} (FZU ASCR, Prague):
[1] D. Krejcirik, P. Siegl and J. Zelezny: On the similarity of Sturm-Liouville operators with non-Hermitian boundary conditions to self-adjoint and normal operators, preprint available at arXiv:1108.4946;
[2] D. Krejcirik and P. Siegl: PT-symmetric models in curved manifolds}, Journal of Physics A: Mathematical and Theoretical, 43 (2010), 485204 (30pp).
 
             
             
             
                
                
             
                
             Symmetries in Quantum Physics 2017
            Symmetries in Quantum Physics 2017
        