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Example 1.
First create a vector bundle over M with base coordinates [t, x, y, z] and fiber coordinates [z1, z2, w1, w2].
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| (2.1) |
Define a spacetime metric g on M.
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| (2.2) |
Define an orthonormal frame on M with respect to the metric g.
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| (2.3) |
Calculate the solder form sigma from the frame F.
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| (2.4) |
Calculate the spin-connection for the solder form sigma.
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| (2.5) |
Example 2.
Define a rank 1 spinor phi. Calculate the covariant derivative of phi. Calculate the directional derivatives of phi.
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| (2.6) |
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| (2.7) |
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| (2.8) |
M >
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| (2.9) |
M >
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| (2.10) |
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| (2.11) |
Example 3.
Check that the covariant derivative of sigma vanishes. Because sigma is a spin-tensor, both connections are required. Calculate the Christoffel connection for the metric g.
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| (2.12) |
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| (2.13) |
Define an epsilon spinor and check that its covariant derivative vanishes.
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| (2.14) |
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| (2.15) |
Example 4.
Calculate the curvature spin-tensor for the spin-connection Gamma2.
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| (2.16) |
The curvature tensor R for the Christoffel connection can be expressed in terms of the curvature spin-tensor SpinR, its complex conjugate barSpinR and the bivector solder forms S and barS by the identity
2*R^i_{jhk} = S^i_j_A^B*R^A_{Bhk} + S^i_j_A'^B'*R^A'_{B'hk} (*)
Let's check this formula for the Christoffel connection Gamma1 and the spin-connection Gamma2. First calculate the curvature tensor for Gamma1.
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| (2.17) |
Calculate the complex conjugate of the spinor curvature SpinR.
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| (2.18) |
Calculate the bivector soldering forms S and barS.
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| (2.19) |
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| (2.20) |
The first term on the right-hand side of (*) is
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| (2.21) |
The second term on the right-hand side of (*) is
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| (2.22) |
M >
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| (2.23) |
M >
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| (2.24) |
M >
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| (2.25) |