English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

For m^2 < a^2 + q^2, with m, a, and q respectively the source mass, angularmomentum per unit mass, and electric charge, the Kerr--Newman (KN) solution ofEinstein's equation reduces to a naked singularity of circular shape, enclosinga disk across which the metric components fail to be smooth. By considering theHawking and Ellis extended interpretation of the KN spacetime, it is shownfirst that, similarly to the electron-positron system, this solution presentsfour inequivalent classical states. Next, it is shown that due to thetopological structure of the extended KN spacetime it does admit states withhalf-integral angular momentum. This last property is corroborated by the factthat, under a rotation of the space coordinates, those inequivalent statestransform into themselves only after a 4pi rotation. As a consequence, itbecomes possible to naturally represent them in a Lorentz spinor basis. Thestate vector representing the whole KN solution is then constructed, and itsevolution is shown to be governed by the Dirac equation. The KN solution canthus be consistently interpreted as a model for the electron-positron system,in which the concepts of mass, charge and spin become connected with thespacetime geometry. Some phenomenological consequences of the model areexplored.Comment: 19 pages, 6 figures. References added, section 2 enhanced, an  appendix and one figure adde

Kerr–Newman Solution as a Dirac Particle