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In differential geometry and mathematical physics, a spin connection is a connection on a spinor bundle. It is induced, in a canonical manner, from the affine connection. It can also be regarded as the gauge field generated by local Lorentz transformations. In some canonical formulations of general relativity, a spin connection is defined on spatial slices and can also be regarded as the gauge field generated by local rotations. ==Definition== Let be the local Lorentz frame fields or vierbein (also known as a tetrad), which is a set of orthogonal space time vector fields that diagonalize the metric tensor : where is the spacetime metric and is the Minkowski metric. Here, Latin letters denote the local Lorentz frame indices; Greek indices denote general coordinate indices. This simply expresses that , when written in terms of the basis , is locally flat. The vierbein field indices can be raised or lowered by the metric and/or . For example, . The spin connection is given by : where is the affine connection. Or purely in terms of the vierbein field as〔M.B. Green, J.H. Schwarz, E. Witten, "Superstring theory", Vol. 2.〕 : which by definition is anti-symmetric in its internal indices . The spin connection defines a covariant derivative on generalized tensors. For example its action on is : 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「Spin connection」の詳細全文を読む スポンサード リンク
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