翻訳と辞書 Words near each other ・ Barrett-Byam Homestead ・ Barrett-Chumney House ・ Barrett-Faulkner House ・ Barrett-Jackson ・ Barrett-Lennard baronets ・ Barretta ・ Barrettali ・ Barrette ・ Barrette (song) ・ Barretter ・ Barretthydrus ・ Barrettinelli di Fuori Lighthouse ・ Barrettini ・ Barretto National High School ・ Barretts (barony) ・ Barrett–Crane model ・ Barretville, Tennessee ・ Barrfields ・ Barrfields Pavilion ・ Barrhaven ・ Barrhaven Centre Station ・ Barrhaven Ward ・ Barrhead ・ Barrhead (disambiguation) ・ Barrhead (New) railway station ・ Barrhead Airport ・ Barrhead Branch ・ Barrhead Central railway station ・ Barrhead F.C. ・ Barrhead High School Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Barrett–Crane model ： ウィキペディア英語版 Barrett–Crane model The Barrett–Crane model is a model in quantum gravity which was defined using the Plebanski action. The $B$ field in the action is supposed to be a $so(3,\; 1)$-valued 2-form, i.e. taking values in the Lie algebra of a special orthogonal group. The term :$B^\; \backslash wedge\; B^$ in the action has the same symmetries as it does to provide the Einstein–Hilbert action. But the form of :$B^$ is not unique and can be posed by the different forms: *$\backslash pm\; e^i\; \backslash wedge\; e^j$ *$\backslash pm\; \backslash epsilon^\; e\_k\; \backslash wedge\; e\_l$ where $e^i$ is the tetrad and $\backslash epsilon^$ is the antisymmetric symbol of the $so(3,\; 1)$-valued 2-form fields. The Plebanski action can be constrained to produce the BF model which is a theory of no local degrees of freedom. John W. Barrett and Louis Crane modeled the analogous constraint on the summation over spin foam. The Barrett–Crane model on spin foam quantizes the Plebanski action, but its path integral amplitude corresponds to the degenerate $B$ field and not the specific definition :$B^\; =\; e^i\; \backslash wedge\; e^j$, which formally satisfies the Einstein's field equation of general relativity. However, if analysed with the tools of loop quantum gravity the Barrett–Crane model gives an incorrect long-distance limit (), and so the model is not identical to loop quantum gravity. ==See also== * EPRL model 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Barrett–Crane model」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.