Matchete`

Matchete`

NonCommutativeMultiply

NonCommutativeMultiply[factor₁, factor₂, …]

is used for all spin chain products involving spinors and Dirac matrices.

factor₁ ** factor₂ ** …

is an alternative input for NonCommutativeMultiply.

Details and Options

NonCommutativeMultiply distributes over Plus.
Factors that are trivial in Dirac space are automatically extracted from NonCommutativeMultiply to appear in an ordinary Times.
The nontrivial objects are DiracProducts and fermion Fields.
Closed spin chains are considered trivial w.r.t. NonCommutativeMultiply.

Examples

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Basic Examples (1)

NonCommutativeMultiply keeps track of ordered products in spin chains, e.g., for a fermion field ψ we have

Properties & Relations (2)

NonCommutativeMultiply automatically distributes over sums and extracts trivial factors (here for a fermion field ψ):

Neighboring DiracProducts are automatically merged inside NonCommutativeMultiply:

Tech Notes

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