← All parts of this equation

Equation 21 · Part 1 · The Entry a Relabeling Cannot Write

Symbol D_Lambda

DΛ:=Hf−Λ†(Hc).D_\Lambda := H_f - \Lambda^\dagger(H_c).
DΛD_\Lambda

What this part means

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

Its job in the formula

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

The passage around this formula

That pullback is the object this article is built around: DΛ:=Hf−Λ†(Hc)D_\Lambda := H_f - \Lambda^\dagger(H_c). DΛD_\Lambda is Hermitian on Hf\mathcal H_f — a positive, unital map applied to a self-adjoint input stays self-adjoint — and it carries units of energy, since both terms do. Its state-dependent reading,

Read this part in the article →

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.

Open the illustrated subscripts: which member of a family? guide →

See this notation across published equations →

Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.