An EPR-channel consists of two Hilbert spaces, H A and H B , and of a density operator sitting on the their direct product space H AB. The channel is triggered by a von Neumann measurement on H A , resulting in a state (density operator) ω A. Because a measurement in H A can be considered as a measurement in H AB equally well, it induces a new state in H AB and, hence, a new state, ω B , in H B...

We show that various kinds of one-photon quantum states studied in the field of quantum optics admit ladder operator formalisms and have the generally deformed oscillator algebraic structure. The two-photon case is also considered. We obtain the ladder operator formalisms of two general states defined in the even/odd Fock space. The two-photon states may also have a generally deformed oscillato...

One electron system minimally coupled to a quantized radiation field is considered. It is assumed that the quantized radiation field is massless, and no infrared cutoff is imposed. The Hamiltonian, H, of this system is defined as a self-adjoint operator acting on L2(R3) ⊗ F ∼= L2(R3;F), where F is the Boson Fock space over L2(R3 × {1, 2}). It is shown that the ground state, ψg, of H belongs to ...

We show that various kinds of one-photon quantum states studied in the field of quantum optics admit ladder operator formalism and bear generally deformed oscillator algebraic structure. The two-photon case is also considered. We obtain the ladder operator formalisms of two general states defined in the even/odd Fock space. The two-photon states also bear generally deformed oscillator algebraic...

We show that various kinds of one-photon quantum states studied in the field of quantum optics admit ladder operator formalisms and have the generally deformed oscillator (GDO) algebraic structure. The two-photon case is also considered. We obtain the ladder operator formalisms of two general states defined in the even/odd Fock space. The two-photon states may also have a GDO algebraic structur...

Relativistic effects are important in the electrons’ dynamics and bound state energies in heavy atoms and molecules. When the nucleii involved are heavily charged, the velocities of the electrons of the inner layers are quite large, and so nonrelativistic modelling will lead to important errors. The usual strategies to address this issue are : either use nonrelativistic models together with rel...

In the model where two massive scalar particles interact by the ladder exchanges of massless scalar particles (Wick-Cutkosky model), we study in light-front dynamics the contributions of different Fock sectors (with increasing number of exchanged particles) to full normalization integral and electromagnetic form factor. It turns out that two-body sector always dominates. At small coupling const...

One electron system minimally coupled to a quantized radiation field is considered. It is assumed that the quantized radiation field is massless, and no infrared cutoff is imposed. The Hamiltonian, H, of this system is defined as a self-adjoint operator acting on L2(R3) ⊗ F , where F is the Boson Fock space over L2(R3 × {1, 2}). It is shown that the ground state, ψg, of H belongs to ∩k=1D(1 ⊗Nk...

The paper extends quadratic optimal control theory to weakly regular linear systems, a rather broad class of infinite-dimensional systems with unbounded control and observation operators. We assume that the system is stable (in a sense to be defined) and that the associated Popov function is bounded from below. We study the properties of the optimally controlled system, of the optimal cost oper...