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Equation 78 · Part 2 · A Reference Frame Becomes Classical by Publishing Its Orientation

superscript

σ(n)\boldsymbol\sigma^{(n)}
superscript

What this part means

A raised number can be a power. When it is a label or bound, it selects a case or the upper limit of a sum; the formula’s structure distinguishes these uses.

Its job in the formula

A raised mark can be a power or an index. Its position and the surrounding notation determine which.

The passage around this formula

Let J\mathbf J be the spin- j angular-momentum operator and σ(n)\boldsymbol\sigma^{(n)} the Pauli vector for probe n . A candidate rotationally invariant interaction is

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Learn the underlying idea

An exponent tells how a base is used in multiplication. In x³, x is the base and 3 is the exponent: x³ = x × x × x.

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