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.
Adjoint graph inf-sup for ultraweak Poisson on connected Lipschitz polyhedra
Statement
Assume Countable Choice. For every bounded connected Lipschitz polyhedron , , and every finite conforming shape-regular simplicial mesh, give its /global-quotient product norm and the full broken graph norm of Ultraweak Poisson DPG spaces and plan-consistent bilinear form. With from A topology-free bounded lifting of every ultraweak Poisson load, the primal and adjoint bounds are Both constants are independent of the mesh. The bounded operator and its Riesz trial-to-test map are boundedly invertible, with inverse norms at most . No simple-connectivity or connected-boundary hypothesis is required; connected polyhedra with holes are included.
Facts & Assumptions
Given: Countable Choice, the stated connected Lipschitz polyhedron and finite mesh, and the exact real trial/test norms and bilinear form.
Countable Choice is the hypothesis for the Hilbert and Riesz interfaces used below. (The Axiom of Countable Choice ())
The product trial and broken test spaces are real Hilbert spaces: their factors, global trace quotient ranges, factors and factors have the stated real Hilbert structures. ( with the integral pairing is a Hilbert space, Ultraweak Poisson skeleton spaces are Hilbert trace quotients, H(div) is Hilbert and H0(div) is closed, The Sobolev space is a Hilbert space)
The real bilinear form defines a bounded operator with . (The ultraweak Poisson DPG bilinear form is bounded)
The trial operator has trivial kernel: implies . (The ultraweak Poisson trial operator has trivial kernel)
There is a linear with and . (A topology-free bounded lifting of every ultraweak Poisson load)
The real Hilbert Riesz map is an isometric linear bijection. (Riesz representation for Hilbert spaces)
The formulation fixes the five signs of , the real trial/test spaces and the full broken graph norm. (Ultraweak Poisson DPG spaces and plan-consistent bilinear form)
Proof
The bounded form [F2] defines , and [F4] makes onto. By [F3], is injective. For each , , so injectivity gives . Therefore , , and the dual norm identity gives the primal bound.
For , set and . Then , so , while [F4] and [F5] give . Since , , and this proves the adjoint bound; for the bound is immediate.
Define . By [F2], . Since , and [F4] and [F5] give . The lifting constant depends only on a fixed-domain Poincaré constant, so both graph inf-sup bounds are uniform over the stated mesh family; the construction uses no simple-connectivity or connected-boundary condition.
Depends on
- Ultraweak Poisson DPG spaces and plan-consistent bilinear form
- Ultraweak Poisson skeleton spaces are Hilbert trace quotients
- $L^2$ with the integral pairing is a Hilbert space
- The Sobolev space $H^1$ is a Hilbert space
- H(div) is Hilbert and H0(div) is closed
- A topology-free bounded lifting of every ultraweak Poisson load
- The ultraweak Poisson trial operator has trivial kernel
- The ultraweak Poisson DPG bilinear form is bounded
- Riesz representation for Hilbert spaces
- The Axiom of Countable Choice ($\mathrm{AC}_\omega$)
Used by
Dependency tree · two levels
53 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
- Jay Gopalakrishnan and Weifeng Qiu, An analysis of the practical DPG method (standard reference, not scraped)
- Leszek Demkowicz and Jay Gopalakrishnan, Analysis of the DPG method for the Poisson equation (standard reference, not scraped)
- Leszek Demkowicz, Mathematical Theory of Finite Elements (standard reference, not scraped)
- Carstensen, Demkowicz, and Gopalakrishnan, A Posteriori Error Control for DPG Methods (standard reference, not scraped)