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The cryptohermitian smeared-coordinate representation of wave functions

Quantum Physics 2011-09-02 v1 Mathematical Physics math.MP

Abstract

The one-dimensional real line of coordinates is replaced, for simplification or approximation purposes, by an N-plet of the so called Gauss-Hermite grid points. These grid points are interpreted as the eigenvalues of a tridiagonal matrix q0\mathfrak{q}_0 which proves rather complicated. Via the "zeroth" Dyson-map Ω0\Omega_0 the "operator of position" q0\mathfrak{q}_0 is then further simplified into an isospectral matrix Q0Q_0 which is found optimal for the purpose. As long as the latter matrix appears non-Hermitian it is not an observable in the manifestly "false" Hilbert space H(F):=RN{\cal H}^{(F)}:=\mathbb{R}^N. For this reason the optimal operator Q0Q_0 is assigned the family of its isospectral avatars hα\mathfrak{h}_\alpha, α=(0,)1,2,...\alpha=(0,)\,1,2,.... They are, by construction, selfadjoint in the respective α\alpha-dependent image Hilbert spaces Hα(P){\cal H}^{(P)}_\alpha obtained from H(F){\cal H}^{(F)} by the respective "new" Dyson maps Ωα\Omega_\alpha. In the ultimate step of simplification, the inner product in the F-superscripted space is redefined in an {\it ad hoc}, α\alpha-dependent manner. The resulting "simplest", S-superscripted representations Hα(S){\cal H}^{(S)}_\alpha of the eligible physical Hilbert spaces of states (offering different dynamics) then emerge as, by construction, unitary equivalent to the (i.e., indistinguishable from the) respective awkward, P-superscripted and α\alpha-subscripted physical Hilbert spaces.

Keywords

Cite

@article{arxiv.1107.1770,
  title  = {The cryptohermitian smeared-coordinate representation of wave functions},
  author = {Miloslav Znojil},
  journal= {arXiv preprint arXiv:1107.1770},
  year   = {2011}
}

Comments

13. pp, 3 figs