Hiroshi Enatsu

Hiroshi Enatsu (12 September 1922 – 4 August 2019) was a Japanese theoretical physicist who contributed to a relativistic Hamiltonian formalism in quantum field theory.

Academic works

Enatsu has found that the commutation relation

psi (x, \tau), \psi ^*(x', \tau)= \delta ( x - x' )

in a relativistic Hamiltonian formalism
is equivalent to that in the conventional non-relativistic Hamiltonian formalism of quantum field theory,
where psi, \phi= \psi \phi - \phi \psi is the commutator,
$x$ is space-time coordinates,
$\tau$ is proper time,
$\psi ^*$ is Hermitian adjoint of $\psi$,
and $\delta (x)$ is the Dirac delta function,
with the aid of the relation

$\epsilon ( x - x' ) \epsilon ( \tau - \tau' )=1$.

Here,
a step function $\epsilon ( x )$ follows $\epsilon ( x )=1$ for $0 < x$,
and $\epsilon ( x )=-1$ for $x < 0$.

Biography

Early stage

Enatsu was born on 12 September 1922 in Miyakonojō as a son of Eizo and Fumi (Kuroiwa) Enatsu.
Miyakonojō is a town within the territory of the former Satsuma Domain,
and it was rather natural for Enatsu to receive an education in Kagoshima.
So, he spent in Kagoshima for secondary education and junior college.

Encounter with Hideki Yukawa

In the last year of junior college,
Hideki Yukawa made a lecture on meson theory at Kagoshima.
After listening to the lecture,
Enatsu became interested in Yukawa and meson theory,
so he decided to study under Yukawa.
He studied on meson theory under Yukawa in undergraduate course.
He received Bachelor of Science from Kyoto Imperial University in 1944.
He received Doctor of Science. from Kyoto Imperial University in 1953 under Yukawa.
Enatsu was an assistant under Yukawa at Kyoto University from 1946 to 1957.
Enatsu was a research assistant at Columbia University in New York City from 1952 to 1953.

Encounter with Niels Bohr

Enatsu was a visiting member of the Institute for Theoretical Physics in Copenhagen from 1955 to 1956.
During his stay in Copenhagen,
he could ask some questions to Bohr almost every week.
It was a special treatment.

Professor at Ritsumeikan University

In 1957,
Enatsu was an assistant professor and inaugurated a professor at Ritsumeikan University in Kyoto.
From 1971 to 1972,
he was also the dean of faculty of science and engineering at Ritsumeikan University.
In 1988,
he retired from a professor at Ritsumeikan University in Kyoto, and has been a professor emeritus.
In 1997.
he received the 3rd class of the Order of the Sacred Treasure.
Enatsu died on 4 August 2019 in KyotoIntelligence: Dr. Hiroshi Enatsu
/ref>

Notes

Research articles

On the Photodisintegration of the Deuteron (Pseudoscalar Meson Theory.), December 1949

On the Nuclear Forces, February 1950

On the Interaction of Mesons and Nucleons, September 1950

On the Mass of Cohesive Meson and the Mass Difference Of Nucleon, April 1951

On the Mass of Cohesive Meson and the Mass Difference of Nucleons, II, June 1951

On the Mass Difference of Nucleons and the Cohesive Mesons, October 1951

On the Self-energies of Mesons, October 1951

On the Self-Energies of Nucleons, October 1951

Self-Energies of Nucleons and the Mass Spectra of Heavy Particles, February 1952

Mass Spectrum of Elementary Particles I: Eigenvalue Problem in Space-time, February 1954

Mass Spectrum of Elementary Particles, II, September 1954

Theory of Unstable Heavy Particles, July 1954

Relativistic quantum mechanics and mass-quantization, 1956

Relativistic Hamiltonian Formalism in Quantum Field Theory and Micro-Noncausality, August 1963

Covariant Hamiltonian Formalism for Particles of any Spin and Nonzero Mass, 1968

Micro-noncausal theory of the hydrogen atom 1971

Covariant Hamiltonian formalism for quantized fields and the hydrogen mass levels, 1975

On the hyperfine structure splittings of hydrogen, 1975

Proton-proton scattering problem in a covariant Hamiltonian formalism, 1976

Four-dimensional tensor forces and electric quadrupole moments in the bound-states of the deuteron, 1976

Micrononcausal euclidean wave functions for hadrons, February 1978

Hyperfine structure splittings of the hydrogen atom in a covariant Hamiltonian formalism, 1983

Bethe-Salpeter type equations for a covariant Hamiltonian formalism in quantum field theory, 1984

Quantization of masses of elementary particles with micrononcausal structures, October 1986

Quantization of masses of elementary particles with micrononcausal structures 1987

Quantization of the mass of the W-boson in the Weinberg-Salam theory, 1988

References

* Levere Hostler
"Quantum field theory of particles of indefinite mass. II. An electromagnetic model", 1981
* John R. Fanchi & Weldon J. Wilson
"Relativistic many-body systems: Evolution-parameter formalism", 1983
* Matej Pavsic
"PseudoEuclidean signature harmonic oscillator, quantum field theory and vanishing cosmological constant", 1998
* Juan P. Aparcio, Fabian H. Gaioli, and Edgardo T. Garcia Alvarez
"Proper Time Derivatives in Quantum Mechanics", 1998
* Edgardo T. Garcia Alvarez & Fabian H. Gaioli
"Covariant Hamiltonian Formalisms for Particles and Antiparticles", 1999
* (Eds.) Rosolino Buccheri, Metod Saniga & William Mark Stuckey, "The Nature of Time: Geometry, Physics and Perception", pp. 173-pp. 174, 2003 (Springer).
* Ed Seidewitz
"Foundations of a Spacetime Path Formalism for Relativistic Quantum Mechanics", November 2006

{{DEFAULTSORT:Enatsu, Hiroshi
Japanese physicists
Academic staff of Ritsumeikan University
Academic staff of Kyoto University
Japanese expatriates in the United States
Kyoto University alumni
Kagoshima University alumni
People from Miyakonojō
1922 births
2019 deaths