翻訳と辞書 Words near each other ・ Synchronized swimming at the Asian Games ・ Synchronized swimming at the Pan American Games ・ Synchronized swimming at the Summer Olympics ・ Synchronizer ・ Synchronizer (algorithm) ・ Synchronizing ・ Synchronizing word ・ Synchronoff ・ Synchronoptic view ・ Synchronous Backplane Interconnect ・ Synchronous CDMA ・ Synchronous circuit ・ Synchronous condenser ・ Synchronous conferencing ・ Synchronous context-free grammar ・ Synchronous coordinates ・ Synchronous culture ・ Synchronous Data Flow ・ Synchronous Data Link Control ・ Synchronous dynamic random-access memory ・ Synchronous Ethernet ・ Synchronous flowering ・ Synchronous frame ・ Synchronous grid of Continental Europe ・ Synchronous idle ・ Synchronous learning ・ Synchronous Meteorological Satellite ・ Synchronous motor ・ Synchronous network ・ Synchronous optical networking 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 Synchronous coordinates ： ウィキペディア英語版 Synchronous coordinates In general relativity, a synchronous reference system is a coordinate system in which the metric takes the form :$ds^2=-dt^2+h\_dx^adx^b$, where the Latin indices ''a'' and ''b'' are summed over the ''spatial'' directions and $h\_$ is a spatial metric. Any metric can locally be put into this form by a coordinate transformation. This coordinate condition is called "synchronous" because the ''t'' coordinate defines proper time for all comoving observers. However, it is not uniquely defined, and therefore is not a gauge, as the spacelike hypersurface at $t=0$ can be chosen arbitrarily. Another problem with the reference system is that caustics can occur which cause the gauge choice to break down. These problems have caused some difficulties doing cosmological perturbation theory in this system, but the problems are now well understood. Synchronous coordinates are generally considered the most efficient reference system for doing calculations, and are used in many modern cosmology codes, such as CMBFAST. They are also useful for solving theoretical problems in which a spacelike hypersurface needs to be fixed, as with spacelike singularities. See also Normal coordinates. ==References== *. See ''section 7.2''. * *. See section 97. 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「Synchronous coordinates」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.