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Equation 1 · Part 4 · How Fast Can a Horizon Learn Which Path You Took?

fraction

∣Ψ(0)⟩=∣0⟩+∣1⟩2⊗∣hin⟩.|\Psi(0)\rangle= \frac{|0\rangle+|1\rangle}{\sqrt 2}\otimes|h_{\rm in}\rangle .
fraction

What this part means

Divide the expression above the line by the one below it.

Its job in the formula

The expression above the fraction bar is divided by the complete expression below it. The denominator must not be zero.

The passage around this formula

Begin with an equal superposition of two localized alternatives, ∣Ψ(0)⟩=∣0⟩+∣1⟩2⊗∣hin⟩|\Psi(0)\rangle= \frac{|0\rangle+|1\rangle}{\sqrt 2}\otimes|h_{\rm in}\rangle . The labels zero and one denote paths, not energy eigenstates. After the system’s long-range field interacts with the inaccessible degrees of freedom, an idealized final pure state has the form

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Learn the underlying idea

A fraction a/b means a divided by b. The top number is the numerator; the bottom number is the denominator, and it cannot be zero.

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Sources cited in the article section

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