Trace formulae for Schrödinger systems on graphs

For Schrödinger systems on metric graphs with d'-type conditions at the central vertex, firstly, we obtain precise description for the square root of the large eigenvalue up to the o(1/n)-term. Secondly, the regularized trace formulae for Schrödinger systems are calculated with some techniques in classical analysis. Finally, these formulae are used to obtain a result of inverse problem in the spirit of Ambarzumyan.

Trace formulae for Schrödinger systems on graphs

For Schrödinger systems on metric graphs with d'-type conditions at the central vertex, firstly, we obtain precise description for the square root of the large eigenvalue up to the o(1/n)-term. Secondly, the regularized trace formulae for Schrödinger systems are calculated with some techniques in classical analysis. Finally, these formulae are used to obtain a result of inverse problem in the spirit of Ambarzumyan.

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  • Thus, the right hand side of (5.2) is exactly 0 , the test function Yk,0makes the functional (A2Y, Y )/||Y ||2 achieve its minimum value and is thus the Şrst eigenfunction. Substituting Yk,0into the equation (2.1), we obtain qj(x) = 0, j = 1, 2,· · · , d. The proof is Şnished. 2