This particle is one of Poincaré group's massless representations which, along with ordinary massless particles, was classified by Eugene Wigner in 1939.
[1] Historically, a compatible theory that could describe this elementary particle was unknown; however, 75 years after Wigner's classification, the first local action principle for bosonic continuous spin particles was introduced in 2014,[2] and the first local action principle for fermionic continuous spin particles was suggested in 2015.
[3] It has been illustrated that this particle can interact with matter in flat spacetime.
[4][5] Supersymmetric continuous spin gauge theory has been studied in three[6] and four[7][8] spacetime dimensions.
In condensed matter systems, CSPs can be understood as massless generalizations of the anyon.