Symbol S
S is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Published equation contexts
The derivation behind this trade-off runs through the ten generators of the Poincaré algebra rather than through anything special to a particular particle. The boost generator is one fixed physical object for a given one-particle state; writing it as a symmetrized combination of a position candidate and the energy only closes the algebra’s commutation relations correctly if either the position candidate absorbs a spin-momentum term, yielding commuting components and frame dependence, the Newton–Wigner choice, or that term is left attached to the boost generator itself, leaving the position candidate free of it but noncommuting, the covariant choice. Both are legitimate solutions of…
S is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Read it with the definitions, units, and assumptions supplied by the article.
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Equation 62 · Evolutionary Physics
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
The derivation behind this trade-off runs through the ten generators of the Poincaré algebra rather than through anything special to a particular particle. The boost generator is one fixed physical object for a given one-particle state; writing it as a symmetrized combination of a position candidate and the energy only closes the algebra’s commutation relations correctly if either the position candidate absorbs a spin-momentum term, yielding commuting components and frame dependence, the Newton–Wigner choice, or that term is left attached to the boost generator itself, leaving the position candidate free of it but noncommuting, the covariant choice. Both are legitimate solutions of…
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