Physlib

PhyslibAlpha.ProbabilisticTheory.State.NormalEquivalence

Normal states give normal weights

i. Overview

The weight of a normal state is normal: suprema of directed families of nonnegative observables are suprema in the whole space, where the state is normal.

ii. Key results

  • `UnitalPositiveLinearMap.IsNormal.toWeight_isNormal` : normal states give normal weights.

1 declaration

theorem

Normal states induce normal weights

Let EE be a space of observables and let s∈S[R,E]s \in \mathcal{S}[\mathbb{R}, E] be a state on EE. If ss is a normal state, then the weight induced by ss, denoted by s.toWeights.\text{toWeight}, is also a normal weight. Here, normality refers to the property that the map preserves the suprema of directed families of nonnegative elements.