Search results for "Pseudo-bosonic operator"
showing 4 items of 4 documents
A class of weak pseudo-bosons and their bi-coherent states
2022
In this paper we extend some previous results on weak pseudo-bosons and on their related bi-coherent states. The role of {\em compatible} functions is discussed in details, and some examples are considered. The pseudo-bosonic ladder operators analysed in this paper generalize significantly those considered so far, and a class of new diagonalizable manifestly non self-adjoint Hamiltonians are deduced.
On the presence of families of pseudo-bosons in nilpotent Lie algebras of arbitrary corank
2019
We have recently shown that pseudo-bosonic operators realize concrete examples of finite dimensional nilpotent Lie algebras over the complex field. It has been the first time that such operators were analyzed in terms of nilpotent Lie algebras (under prescribed conditions of physical character). On the other hand, the general classification of a finite dimensional nilpotent Lie algebra $\mathfrak{l}$ may be given via the size of its Schur multiplier involving the so-called corank $t(\mathfrak{l})$ of $\mathfrak{l}$. We represent $\mathfrak{l}$ by pseudo-bosonic ladder operators for $t(\mathfrak{l}) \le 6$ and this allows us to represent $\mathfrak{l}$ when its dimension is $\le 5$.
A description of pseudo-bosons in terms of nilpotent Lie algebras
2017
We show how the one-mode pseudo-bosonic ladder operators provide concrete examples of nilpotent Lie algebras of dimension five. It is the first time that an algebraic-geometric structure of this kind is observed in the context of pseudo-bosonic operators. Indeed we don't find the well known Heisenberg algebras, which are involved in several quantum dynamical systems, but different Lie algebras which may be decomposed in the sum of two abelian Lie algebras in a prescribed way. We introduce the notion of semidirect sum (of Lie algebras) for this scope and find that it describes very well the behaviour of pseudo-bosonic operators in many quantum models.
MR3535311 Reviewed Inoue, H.(J-KYUSGM); Takakura, M.(J-FUE-AM) Regular biorthogonal pairs and pseudo-bosonic operators. (English summary) J. Math. Ph…
2017
Given a pair of operators a and b acting on a Hilbert space H, such that [a,b]=1, the authors give a method to construct a regular bi-orthogonal pair of sequences in H. They study the relationship between the conditions on a,b,a†,b† and the operators Ae,Be,A†e,B†e, considered by one of the authors in a previous paper, in the set-up of a general theory of bi-orthogonal pair sequences. Then they give a method to construct operators A and B with the so-called D-pseudo bosons conditions, i.e. the commutation rule and some assumptions, on a dense subspace D of H, considered in the literature. Finally, some physical examples are given.