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Equation 28 · Part 1 · The Valley of Stability Is a Fitness Landscape

Symbol delta

δ(A)\delta(A)
δ\delta

What this part means

delta is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

delta is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

where α\alpha , β\beta , and γ\gamma collect the volume, surface, Coulomb, and asymmetry contributions and the pairing term δ(A)\delta(A) shifts the curve up or down depending on whether N and Z are both even or both odd. For odd A , exactly one of N , Z is even and the pairing term vanishes, giving a single parabola with one minimum: one value of Z at that mass number is the most tightly bound, and every other isobar…

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A function assigns an output to each allowed input. The expression f(x) means “apply f to x”.

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Sources cited in the surrounding passage

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