On the analytical approach to infinite-mode Boson-Gaussian states
- URL: http://arxiv.org/abs/2506.04537v1
- Date: Thu, 05 Jun 2025 01:07:01 GMT
- Title: On the analytical approach to infinite-mode Boson-Gaussian states
- Authors: Jorge R. Bolaños-Servín, Roberto Quezada, Josué I. Rios-Cangas,
- Abstract summary: We use Yosida approximations to define integrability of possibly unbounded observables with respect to a state $rho$ ($rho$-integrability)<n>It turns out that all elements of the commutative $*$-algebra generated by a possibly unbounded $rho$-integrable observable $A$, denoted by $langle Arangle$, are normal and $rho, $-integrable.
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- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We develop an analytical approach to quantum Gaussian states in infinite-mode representation of the Canonical Commutation Relations (CCR's), using Yosida approximations to define integrability of possibly unbounded observables with respect to a state $\rho$ ($\rho$-integrability). It turns out that all elements of the commutative $*$-algebra generated by a possibly unbounded $\rho$-integrable observable $A$, denoted by $\langle A\rangle$, are normal and $\rho \, $-integrable. Besides, $\langle A\rangle$ can be endowed with the well-defined norm $\|\cdot\|_\rho:= {\rm tr}\,(\rho |\cdot| )$. Our approach allows us to rigorously establish fundamental properties and derive key formulae for the mean value vector and the covariance operator. We additionally show that the covariance operator $S$ of any Gaussian state is real, bounded, positive, and invertible, with the property that $S-iJ\geq 0$, being $J$ the multiplication operator by $-i$ on $\ell_2({\mathbb N})$.
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