3 papers
math-ph2025
Representations of Josephson junction on the unit circle and the derivations of Mathieu operators and Fraunhofer patterns
Toshiyuki Fujii, Fumio Hiroshima, Satoshi Tanda
The Hamiltonian J of the Josephson junction is introduced as a self-adjoint operator on l2 tensor l2. It is shown that J can also be realized as a self-adjoint operator HS1 on L2(S…
math-ph2025
Conjugate Operators of 1D-harmonic Oscillator
Fumio Hiroshima, Noriaki Teranishi
A conjugate operator of one-dimensional harmonic oscillator is defined by an operator satisfying canonical commutation relation $[N,T]=-i\one$ on some domain but not necess…
math-ph2024
Self-adjointness of unbounded time operators
Fumio Hiroshima, Noriaki Teranishi
Time operators for an abstract semi-bounded self-adjoint operator with purely discrete spectrum is considered. The existence of a bounded self-adjoint time operator for …