Symbol X
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Why this formula appears here
Because [X,Y] is itself proportional to the identity, it commutes with both X and Y , so every higher term in the Baker–Campbell–Hausdorff expansion of vanishes identically, at all orders, with no small-loop approximation required:
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Symbol Y
Y is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
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Read this expression with the definitions, units, and assumptions supplied by the article.
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Equation 34 · Evolutionary Physics
The Clock That Comes Back Wrong by Exactly Its Mass
This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text.
Because [X,Y] is itself proportional to the identity, it commutes with both X and Y , so every higher term in the Baker–Campbell–Hausdorff expansion of vanishes identically, at all orders, with no small-loop approximation required:
Equation guide → · Article →