Editing Supergravity (section)

===Supergravity===
The first model of 4-dimensional supergravity (without this denotation) was formulated by Dmitri Vasilievich Volkov and Vyacheslav A. Soroka in 1973,<ref name ="Volkov Soroka">{{cite journal | last1 = Volkov | first1 = D.V. | last2 = Soroka | first2 = V.A. | year = 1973 | title = Higgs effect for Goldstone particles with spin 1/2 | journal = JETP Letters | volume = 16 | issue = 11| pages = 438–440 | doi=10.1007/BFb0105271 | bibcode = 1973JETPL..18..312V }}</ref> emphasizing the importance of spontaneous supersymmetry breaking for the possibility of a realistic model. The [[Pure 4D N = 1 supergravity|minimal version of 4-dimensional supergravity]] (with unbroken local supersymmetry) was constructed in detail in 1976 by [[Daniel Z. Freedman|Dan Freedman]], [[Sergio Ferrara]] and [[Peter van Nieuwenhuizen]].<ref name="Summary">{{cite journal | last1 = Freedman | first1 = D.Z. | last2 = van Nieuwenhuizen | first2 = P. | last3 = Ferrara | first3 = S. | year = 1976 | title = Progress Toward A Theory Of Supergravity | journal =  Physical Review D| volume =  13| issue = 12| pages = 3214–3218 | doi=10.1103/physrevd.13.3214| bibcode = 1976PhRvD..13.3214F }}</ref>  In 2019 the three were awarded a special [[Breakthrough Prize in Fundamental Physics]] for the discovery.<ref>{{Cite news|url=https://www.cbc.ca/news/technology/supergravity-breakthrough-prize-1.5237900|title=Supergravity scientists share $3M US Breakthrough Prize|work=CBC News}}</ref> The key issue of whether or not the spin 3/2 field is consistently coupled was resolved in the nearly simultaneous paper, by [[Stanley Deser|Deser]] and [[Bruno Zumino|Zumino]],<ref name="DeserZumino">{{cite journal | last1 = Deser | first1 = S. | last2 = Zumino | first2 = B. | year = 1976 | title = Consistent Supergravity | url = https://cds.cern.ch/record/438874| journal =   Physics Letters B| volume =  62| issue = 3| pages = 335–337 | doi=10.1016/0370-2693(76)90089-7| bibcode =  1976PhLB...62..335D}}</ref> which independently proposed the minimal 4-dimensional model. It was quickly generalized to many different theories in various numbers of [[dimensions]] and involving additional (N) supersymmetries. Supergravity theories with N>1 are usually referred to as extended supergravity (SUEGRA). Some supergravity theories were shown to be related to certain [[higher-dimensional]] supergravity theories via [[compactification (physics)|dimensional reduction]] (e.g. N=1, 11-dimensional supergravity is dimensionally reduced on T<sup>7</sup> to 4-dimensional, ungauged, ''N'' = 8 supergravity). The resulting theories were sometimes referred to as [[Kaluza–Klein theory|Kaluza–Klein theories]] as Kaluza and Klein constructed in 1919 a 5-dimensional gravitational theory, that when dimensionally reduced on a circle, its 4-dimensional non-massive modes describe [[electromagnetism]] coupled to [[gravity]].