2008/08/01 by Y. Nogami, Nogami, Y.
Decision Sciences · Physics and Astronomy · #FOS: Physical sciences #Quantum Physics (quant-ph) #Scientific Measurement and Uncertainty Evaluation #quant-ph
paper · pdf · doi:10.48550/arxiv.0808.0164
18 pages
arxiv created 2008/08/01 · openalex publication_date 2008/08/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider a model of a quantized fermion field that is based on the Dirac equation in one dimensional space and re-examine how the fermion number of the vacuum, or the vacuum charge, varies when an external potential is switched on. With this model, fractionization of the vacuum charge has been illustrated in the literature by showing that the external potential can change the vacuum charge from zero to a fractional number. Charge conservation then appears violated in this process. This is because the charge that has been examined in this context is only a part of the total charge of the vacuum. The total charge is conserved. It is not fractionalized unless the Dirac equation has a zero mode. Two other confusing aspects are discussed. One is concerned with the usage of the continuum limit and the other with the regularization of the current operator. Implications of these aspects of the vacuum problem are explored.