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Equation 64 · Part 1 · The Entry a Relabeling Cannot Write

Symbol H_SB

HSB=0H_{SB} = 0
HSBH_{SB}

What this part means

HSH_SB is part of the quantity the equation computes from the expression on the right.

Its job in the formula

HSH_SB is part of the quantity the equation computes from the expression on the right.

The passage around this formula

Two limits inside this one formula answer different questions about how confidently the ledger can be interpreted. First, an uncorrelated, non-interacting bath: set HSBH_{SB} = 0 and let ρ\rho = ρS\rho_S ⊗\otimes |b⟩\rangle⟨\langle b| for any system state ρS\rho_S and any bath eigenstate |b⟩\rangle with HBH_B|b⟩\rangle = EbE_b|b⟩\rangle . Then Δ\Delta EΛ(ρ)E_\Lambda(\rho) = EbE_b for every choice of ρS\rho_S whatsoever — a pure constant, entirely independent of what the system is doing,…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the article section

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