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∣Δx∣≤ρM|\Delta\mathbf x| \le \rho_M

Why this formula appears here

the proper spatial separation within Σ\Sigma between the two charts’ answers, normalized by the spin-to-mass length fixed in the first section. δij\delta_{ij} is dimensionless by construction, symmetric, zero exactly when the two charts coincide, and it has now been checked, not merely asserted, in both directions this kind of construction is required to pass: it vanishes as v/c →\to 0 for any spin, and it vanishes as S →\to 0 for any observer or Lorentz frame. It is bounded above by exactly 1 for the observer-transition case, since |Δ\Deltax\mathbf x| ≤\le ρM\rho_M was shown above to saturate rather than merely approach that value. Both checks are this construction’s kill criterion, run rather than…

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Δ\Delta

Symbol Δ

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xx

Symbol x

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ρM\rho_M

Symbol rho_M

rhoMo_M 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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∣Δx∣≤ρM|\Delta\mathbf x| \le \rho_M

Equation 123 · Evolutionary Physics

The Atlas That Refuses to Close

This equation states a bound: one expression must stay on the indicated side of the other under the article’s assumptions.

the proper spatial separation within Σ\Sigma between the two charts’ answers, normalized by the spin-to-mass length fixed in the first section. δij\delta_{ij} is dimensionless by construction, symmetric, zero exactly when the two charts coincide, and it has now been checked, not merely asserted, in both directions this kind of construction is required to pass: it vanishes as v/c →\to 0 for any spin, and it vanishes as S →\to 0 for any observer or Lorentz frame. It is bounded above by exactly 1 for the observer-transition case, since |Δ\Deltax\mathbf x| ≤\le ρM\rho_M was shown above to saturate rather than merely approach that value. Both checks are this construction’s kill criterion, run rather than…

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