| Title |
On some extensions of the A-model / |
| Authors |
Juršėnas, Rytis |
| DOI |
10.7494/OpMath.2020.40.5.569 |
| Full Text |
|
| Is Part of |
Opuscula Mathematica.. Krakow : AGH University of Science and Technology Press. 2020, vol. 40, no. 5, p. 569-597.. ISSN 1232-9274. eISSN 2300-6919 |
| Keywords [eng] |
finite rank higher order singular perturbation ; cascade (A) model ; peak model ; Hilbert space ; scale of Hilbert spaces ; Pontryagin space ; ordinary boundary triple ; Krein Q-function ; Weyl function ; gamma field ; symmetric operator ; proper extension ; resolvent |
| Abstract [eng] |
The A-model for finite rank singular perturbations of class $\mathfrak{H}_{-m-2}\setminus \mathfrak{H}_{-m-1}$, $m \in \mathbb{N}$, is considered from the perspective of boundary relations. Assuming further that the Hilbert spaces $(\mathfrak{H}_n)_{n\in\mathbb{Z}}$ admit an orthogonal decomposition $\mathfrak{H}^-_n\oplus\mathfrak{H}^+_n$ , with the corresponding projections satisfying $P^\pm_{n+1}\subseteq P^\pm_n$, nontrivial extensions in the A-model are constructed for the symmetric restrictions in the subspaces. |
| Published |
Krakow : AGH University of Science and Technology Press |
| Type |
Journal article |
| Language |
English |
| Publication date |
2020 |
| CC license |
|
