Kohji Hirata

Classical lagrangian theory of Dirac's monopole: Avoiding Dirac's veto

Abstract Redefinition of Diracs action for a charge-monopole system as a certain limit of Wu-Yangs action solves Diracs veto problem. The string variable yμ(τ,σ) plays an essential role in the variation principle.

Dirac's monopoles and action-at-a-distance theory: Classical dynamics

Abstract We redefine Diracs action for charge-monopole systems as a certain limit of Wu-Yangs action in a way which is similar to, but different from, the work of Brandt and Primack. The lagrangian theory thus obtained reproduces, in a simple and straightforward manner, all of the Maxwell-Lorentz equations without recourse to Diracs veto. It also becomes clear that the action-at-a-distance formalism is especially suited for the description of such systems. An action, equations of motion and conserved linear and angular momenta are explicitly given, which do not depend on the string. The existence of a charge-monopole bound state is suggested.

Action-at-a-distance theory of electrodynamics with dirac's monopoles

Abstract A classical action-at-a-distance theory of a charge-monopole system is constructed by use of strings but without recourse to Diracs veto. An action, equations of motion and conserved linear- and angular-momenta are explicitly given which do not depend on the string.

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

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 1930s to mid-1940s which have been clarified in Yukawa Hall Archival Library, Tomonaga Memorial Room and Sakata Memorial Archival Library.

Memorial Archival Libraries of Yukawa, Tomonaga, and Sakata

Yoshinobu Takaiwa∗1, Masako Bando2, Haruyoshi Gotoh3, Hisao Hayakawa4, Kohji Hirata5, Kazuyuki Ito6, Kenji Ito5, Kazuyuki Kanaya7, Daisuke Konagaya8, Michiji Konuma9, Taichiro Kugo10, Chusei Namba11, Tadashi Nishitani12, Masaharu Tanabashi13, Kio Tanaka14, Sho Tanaka15, Fumihiko Ukegawa7 and Tadashi Yoshikawa16 1Tsukuba University of Technology, Tsukuba 305-8521, Japan. 2Aichi University, Nagoya 453-8777, Japan. 3Kyoto University Museum, Kyoto University, Kyoto 606-8501, Japan. 4Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan. 5The Graduate University for Advanced Studies (Sokendai), Hayama 240-0193, Japan. 6Faculty of Literature, Kyoto University, Kyoto 606-8501, Japan. 7Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan. 8Faculty of Business Administration, Ryukoku University, Kyoto 612-8577, Japan. 9Yukawa Institute for Theorertical Physics, Kyoto University, Kyoto 606-8502, Japan and Keio University, Yokohama 223-8521, Japan. 10Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan. 11National Institute for Fusion Science, Toki 509-5292, Japan. 12Kikuchi College of Optometry, Nagoya 461-0001, Japan. 13Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, and Department of Physics, Nagoya University, Nagoya 464-8601, Japan. 14Faculty of Literature, Nara Women’s University, Nara 630-8506, Japan. 15Kyoto University, Kyoto 606-8501, Japan. 16Nagoya Women’s University, Nagoya 467-8507, Japan