Reminiscences

Tomonaga, Sin-itirô

doi:10.1143/ptps.e68.3

Cited by 61 publications

(126 citation statements)

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“…In that work the point of view is expressed, that the wavefunction (and as result the Wigner function, we notice) has no objective value and does not covariantly transform when there are classical interventions. Here we note that in principle equation (19) can be written with four-dimensional Lorentz invariant symbols only, but to do this we have to incorporate in the theory a certain time-like unit vector in a way similar to Tomonaga-Schwinger approach to quantum field theory [28,29]. It is the four-velocity of the frame where the wavefunction collapse occurs (the measuring device frame) relative to the second static observer (watching observer).…”

Section: Matrix-valued Wigner Function and Quantum Liouville Equmentioning

confidence: 99%

Peculiarities of the Weyl-Wigner-Moyal formalism for scalar charged particles

Lev

Семенов

Usenko

2001

J. Phys. A: Math. Gen.

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A description of scalar charged particles, based on the Feshbach -Villars formalism, is proposed. Particles are described by an object that is a Wigner function in usual coordinates and momenta and a density matrix in the charge variable. It is possible to introduce the usual Wigner function for a large class of dynamical variables. Such an approach explicitly contains a measuring device frame. From our point of view it corresponds to the Copenhagen interpretation of quantum mechanics. It is shown how physical properties of such particles depend on the definition of the coordinate operator. The evolution equation for the Wigner function of a single-charge state in the classical limit coincides with the Liouville equation. Localization peculiarities manifest themselves in specific constraints on possible initial conditions.

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Section: Matrix-valued Wigner Function and Quantum Liouville Equmentioning

confidence: 99%

Peculiarities of the Weyl-Wigner-Moyal formalism for scalar charged particles

Lev

Семенов

Usenko

2001

J. Phys. A: Math. Gen.

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“…The idea of evolving a quantum field from any Cauchy surface to any other seems to have originated in the mid 1940's with the work of Tomonaga [1] and Schwinger [2] on relativistic quantum field theory. Tomonaga and Schwinger wanted an invariant generalization of the Schrödinger equation, which describes time evolution of the state of a quantum field relative to a fixed inertial reference frame.…”

Section: Introductionmentioning

confidence: 99%

“…Following [3], we use the term functional evolution to refer to the formulation of dynamical evolution in which one evolves quantities along arbitrary Cauchy surfaces. 1 Thus the Tomonaga-Schwinger equation appears as the analog of the Schrödinger equation, when describing functional evolution. It was (and still is) tacitly assumed that the Tomonaga-Schwinger equation defines the infinitesimal form of unitary evolution of states from one Cauchy surface to another, just as the more familiar (and mathematically more tractable) Schrödinger equation describes the infinitesimal form of unitary evolution between two hyperplanes of constant Minkowskian time.…”

Section: Introductionmentioning

confidence: 99%

Functional evolution of free quantum fields

Torre

Varadarajan

1999

Class. Quantum Grav.

121

156

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We consider the problem of evolving a quantum field between any two (in general, curved) Cauchy surfaces. Classically, this dynamical evolution is represented by a canonical transformation on the phase space for the field theory. We show that this canonical transformation cannot, in general, be unitarily implemented on the Fock space for free quantum fields on flat spacetimes of dimension greater than 2. We do this by considering time evolution of a free Klein-Gordon field on a flat spacetime (with toroidal Cauchy surfaces) starting from a flat initial surface and ending on a generic final surface. The associated Bogolubov transformation is computed; it does not correspond to a unitary transformation on the Fock space. This means that functional evolution of the quantum state as originally envisioned by Tomonaga, Schwinger, and Dirac is not a viable concept. Nevertheless, we demonstrate that functional evolution of the quantum state can be satisfactorily described using the formalism of algebraic quantum field theory. We discuss possible implications of our results for canonical quantum gravity.

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“…This paper was translated in English in 1946. [24] ( Fig.7) The first sentence of the paper was that "Recently Yukawa has made a comprehensive consideration about the basis of the quantum theory of wave fields. In his article he has pointed out the fact that the existing formalism of the quantum field theory is not yet perfectly relativistic".…”

Section: Tomonaga's Super Many-time Theory Was Inspired By Yukawa's Amentioning

confidence: 99%

The Legacy of Hideki Yukawa, Sin-itiro Tomonaga, and Shoichi Sakata: Some Aspects from their Archives

Konuma¹,

Bandō²,

Gotoh³

et al. 2014

Proceedings of the 12th Asia Pacific Physics Conference (APPC12)

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Hideki Yukawa, Sin-itiro Tomonaga and Shoichi Sakata pioneered nuclear and particle physics and left enduring legacies. Their friendly collaboration and severe competition laid the foundation to bring up the active postwar generation of nuclear and particle physicists in Japan. In this presentation we illustrate milestones of nuclear and particle physics in Japan from 1930's to mid-1940's which have been clarified in Yukawa Hall Archival Library, Tomonaga Memorial Room and Sakata Memorial Archival Library.

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Reminiscences

Cited by 61 publications

References 0 publications

Peculiarities of the Weyl-Wigner-Moyal formalism for scalar charged particles

Peculiarities of the Weyl-Wigner-Moyal formalism for scalar charged particles

Functional evolution of free quantum fields

The Legacy of Hideki Yukawa, Sin-itiro Tomonaga, and Shoichi Sakata: Some Aspects from their Archives

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