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K. W. Yuen

Publications and source records attributed to K. W. Yuen.

2 recordsLinked to original sources

WDPhotTools -- A White Dwarf Photometric Toolkit in Python

From data collection to photometric fitting and analysis of white dwarfs to generating a white dwarf luminosity function requires numerous Astrophysical, Mathematical and Computational domain knowledge. The steep learning curve makes it difficult to enter the field, and often individuals have to reinvent the wheel to perform identical data reduction and analysis tasks. We have gathered a wide range of publicly available white dwarf cooling models and synthetic photometry to provide a toolkit that allows (1) visualisation of various models, (2) photometric fitting of a white dwarf with or without distance and reddening, and (3) the computing of white dwarf luminosity functions with a choice of initial mass function, main sequence evolution model, star formation history, initial-final mass relation, and white dwarf cooling model. We have recomputed and compared the effective temperature of the white dwarfs from the Gaia EDR3 white dwarf catalogue. The two independent works show excellent agreement in the temperature solutions.

astro-ph.IM

The quantum mechanical geometric phase of a particle in a resonant vibrating cavity

We study the general-setting quantum geometric phase acquired by a particle in a vibrating cavity. Solving the two-level theory with the rotating-wave approximation and the SU(2) method, we obtain analytic formulae that give excellent descriptions of the geometric phase, energy, and wavefunction of the resonating system. In particular, we observe a sudden $π$-jump in the geometric phase when the system is in resonance. We found similar behaviors in the geometric phase of a spin-1/2 particle in a rotating magnetic field, for which we developed a geometrical model to help visualize its evolution.

quant-ph