Progress of Theoretical Physics
On the Velocity Operator in Quantum Mechanics
Toshiyuki Nishiyama
Abstract
Progress of Theoretical Physics Vol. 8 No. 6 (1952) pp. 655-668 A Quantum Theory of Boson Assemblies, I Toshiyuki Nishiyama Progress of Theoretical Physics Vol. 27 No. 3 (1962) pp. 600-607 Collective Description of a System of Interacting Bose Particles. II Sigenobu Sunakawa, Hiroshi Nakatani and Yoshimatsu Yoko-o Progress of Theoretical Physics Vol. 52 No. 6 (1974) pp. 1784-1797 A Long-Range Attractive Interaction of Rotons in Superfluid 4He Toshiyuki Nishiyama and Shunkichi Sai Progress of Theoretical Physics Vol. 53 No. 2 (1975) pp. 386-399 On the Validity of Collective Variable Description of Bose Systems Minoru Takahashi Progress of Theoretical Physics Vol. 53 No. 5 (1975) pp. 1243-1266 On the Collective Variables in Many-Boson System Shuichiro Yamasaki, Takeji Kebukawa and Sigenobu Sunakawa Progress of Theoretical Physics Vol. 54 No. 2 (1975) pp. 384-395 Ground-State Energy of a Many-Boson System Toshiyuki Nishiyama Progress of Theoretical Physics Vol. 54 No. 2 (1975) pp. 597-599 Momentum Distribution of an Interacting Many-Boson System Toshiyuki Nishiyama Progress of Theoretical Physics Vol. 56 No. 2 (1976) pp. 375-395 A Microscopic Theory of the Interacting Bose System Shosuke Sasaki and Kiyohisa Matsuda Progress of Theoretical Physics Vol. 57 No. 2 (1977) pp. 393-409 Collective Variable Approach to Many-Boson Systems at High Density Toshiyuki Nishiyama and Masakazu Tsujii Progress of Theoretical Physics Vol. 62 No. 6 (1979) pp. 1487-1498 Generalized Solutions to the Gross-Pitaevskii Equation Masakazu Ichiyanagi Progress of Theoretical Physics Vol. 64 No. 4 (1980) pp. 1248-1264 Bose-Einstein Condensation and the Canonical Conjugates to the Density Fluctuations Shuichiro Yamasaki and Masahiko Hirooka Progress of Theoretical Physics Vol. 64 No. 5 (1980) pp. 1565-1576 Momentum Distribution and Ground-State Energy of Liquid 4He at the Absolute Zero Temperature Toshiyuki Nishiyama and Yoiti Watanabe Progress of Theoretical Physics Vol. 67 No. 3 (1982) pp. 726-742 On the Hydrodynamical Model for a Bose Liquid at T=0 Masakazu Ichiyanagi and Masato Ohya Progress of Theoretical Physics Vol. 68 No. 5 (1982) pp. 1482-1503 Quasi-Particle Description of a Degenerate System of Bosons Masahiko Hirooka and Shuichiro Yamasaki