2 papers
math-ph2022
Surgery transformations and spectral estimates of beam operators
Aftab Ali, Muhammad Usman
We introduce type vertex conditions for beam operators, the fourth derivative operator, on metric graphs and study the effect of certain geometrical alterations (graph surgery)…
math-ph2022
Surgery transformations and eigenvalue estimates for quantum graphs with vertex interactions
Aftab Ali, Muhammad Usman
We extend the surgical tool box for quantum graphs to anti-standard and vertex conditions. Monotonicity properties of eigenvalues of graph Laplacian with interactions at…