How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Partial trace over a finite tensor factor
Definition
For a complex vector space , write for the set of linear maps (Linear map between vector spaces over the same field).
Let be finite-dimensional complex inner-product spaces with fixed ordered orthonormal bases and , respectively. The ordered product basis of has the index first. For define by
Rows are output coordinates and columns are input coordinates, as in Coordinate columns and matrices of linear maps relative to ordered bases. If , the sum is empty and equals . The notation means that the second factor is contracted; the first factor and its order are retained.
Facts & Assumptions
Given: Finite-dimensional complex inner-product spaces , the specified ordered orthonormal bases, and .
The ordered product basis identifies the coordinates of with pairs in the displayed factor order (Ordered tensor registers, their inner product, and wire permutations).
A linear map is determined by the images of an ordered basis, whose coordinate columns are unique (Linear map between vector spaces over the same field, A finite list is an ordered basis if and only if every equals for exactly one ; those scalars are the coordinates of in that ordered basis).
Proof
For each basis vector of , prescribe . Each inner and outer sum is finite; when its inner sum is .
By the ordered-basis coordinate property [F2], these prescribed images extend uniquely to a linear map , and its matrix has exactly the displayed entries. Each entry is linear in the entries of , so the resulting assignment is linear. This defines even when either basis is empty.
Depends on
- Ordered tensor registers, their inner product, and wire permutations
- The basis-independent trace of an endomorphism of a finite-dimensional vector space
- Coordinate columns $[v]_{\mathcal B}$ and matrices $[T]_{\mathcal B}^{\mathcal C}$ of linear maps relative to ordered bases
- A finite list $v : n \to V$ is an ordered basis if and only if every $x \in V$ equals $\sum_{i<n} \lambda_i v_i$ for exactly one $\lambda : n \to F$; those scalars are the coordinates of $x$ in that ordered basis
- Linear map between vector spaces over the same field
Used by
- Five-local history-state adiabatic path Algorithm
- One finite abelian hidden-subgroup Fourier sample Algorithm
- Broadcasting Family Definition
- Complementary channels and coherent information Definition
- Ensemble and purification Definition
- Finite quantum mutual, conditional, and conditional mutual information Definition
- Finite-dimensional quantum erasure channel Definition
- Isometric Stinespring representation Definition
- Operational quantum, private, and entanglement-assisted capacities Definition
- Partial trace over the first tensor factor Definition
- Uniform verifier interface with a quantum witness Definition
- A Bell pair has negative quantum conditional entropy Example
- Bell-state Schmidt decomposition and reduced density Example
- Qubit dephasing channel in Kraus and Choi forms Example
- Register endianness and a two-qubit partial trace Example
- Strong subadditivity for a pure GHZ tripartite state Example
- A finite instrument has an isometric coherent record Lemma
- A finite verifier induces an effect on its witness Lemma
- Coherent information equals output entropy minus environment entropy Lemma
- Compression dimension bounds entanglement fidelity Lemma
- Dihedral hidden-state pair combination Lemma
- Discarding the hiding register yields a coset-state mixture Lemma
- Every finite extension is obtained from a purification by a channel Lemma
- Fidelity classical measurement minimum Lemma
- Fourier sample from a generalized-dihedral reflection coset state Lemma
- History state and padded output Lemma
- Joint state support is contained in the tensor product of its marginal supports Lemma
- Optimal Cloner Attains Bound Lemma
- Partial trace contracts the trace norm on Hermitian operators Lemma
- Partial trace contracts trace distance Lemma
- Partial traces of a finite bipartite state are states Lemma
- Positive Marginals Imply Joint Support Lemma
- The finite Weyl twirl is the normalized partial trace Lemma
- An isometry followed by partial trace is a channel Theorem
- Channel data processing for finite quantum relative entropy Theorem
- Circuit-to-adiabatic simulation Theorem
- Every finite state ensemble is obtainable from a purification Theorem
- Every finite-dimensional channel has a finite isometric dilation Theorem
- Fidelity Data Processing Theorem
- Fidelity Purification Characterization Theorem
…and 22 more results.
Dependency tree · two levels
32 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- John Watrous, The Theory of Quantum Information (standard reference, not scraped)
- John Preskill, Quantum Computation, Chapter 2: Foundations I: States and Ensembles (standard reference, not scraped)