Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Weighted Second-Moment Evolution of the State Fluctuation Process
lemmalem:fluctuation-weighted-second-moment-2026bProbabilityAdopt the setting of the fluctuation processes of the controlled -agent dynamics: a transition-rate family on states with control set , a nonempty subset of Euclidean space , and rate bound , an observation-rate family ,…- Let and be natural numbers with and , let be a nonempty subset of Euclidean space , let be a transition-rate family on states with control set and rate bound , and let be a…
Grouping Independence and the Fresh-Start Sigma-Algebra of an Independent-Increment Process
lemmalem:independent-increments-fresh-start-2026aProbabilityLet be a probability space. (a) (Grouping.) Let be a natural number, let be independent random variables on , and let and be disjoint subsets of . Then the -algebras…Existence and Uniqueness of the Nonnegative Square Root of a Nonnegative Real Number
theoremthm:real-nonnegative-square-root-2026aAnalysisLet be the set of real numbers, which by that definition is an ordered field, with order relation , in which every nonempty subset that is bounded above has a least upper bound. Write and for the additive and multiplicative identities of the underlying…- Let be a field, with additive identity , multiplicative identity , additive inverse of an element , and multiplicative inverse of an element . Write and ; a sum of three terms is written without brackets, which is una…
Existence and Uniqueness of the Positive Semi-Definite Square Root
theoremthm:positive-semidefinite-square-root-2026aAnalysisLinear AlgebraLet together with be a complex inner product space with zero vector , and suppose that is finite-dimensional and . Let be a linear operator on that is self-adjoint and positive semi-definite. Then there is exactly…A Positive Semi-Definite Square Root Acts on Eigenvectors by the Nonnegative Square Root
lemmalem:psd-square-root-eigenvector-action-2026bAnalysisLinear AlgebraLet together with be a complex inner product space, and let be a linear operator on that is self-adjoint and positive semi-definite. Let be a real number with , the order being that of the ordered field of real numbe…An Operator with an Orthonormal Eigenbasis is Positive Semi-Definite Exactly When its Eigenvalues are Nonnegative
lemmalem:positive-semidefinite-iff-nonnegative-eigenvalues-2026aAnalysisLinear AlgebraLet together with be a complex inner product space with zero vector . Let be a natural number, let be the initial segment determined by , and let be an -tuple in that is an orthonormal basis of , with comp…Second-Order Expansion of the N-Agent Cost about a Stationary Mean-Field Trajectory
theoremthm:n-agent-cost-expansion-2026cProbabilityAdopt the setting of the fluctuation processes of the controlled -agent dynamics: a transition-rate family on states with control set , a nonempty subset of Euclidean space , and rate bound , an observation-rate family ,…Operators Diagonal in an Orthonormal Basis
lemmalem:orthonormal-diagonal-operator-2026aAnalysisLinear AlgebraLet together with be a complex inner product space. Let be a natural number, let be the initial segment determined by , and let be an -tuple in that is an orthonormal basis of , with components . Let…A Priori Second-Moment Bound for the State Fluctuation Process
lemmalem:fluctuation-state-moment-bound-2026bProbabilityAdopt the setting of the fluctuation processes of the controlled -agent dynamics: a transition-rate family on states with control set , a nonempty subset of Euclidean space , and rate bound , an observation-rate family ,…The Eigenvalues of an Operator with an Orthonormal Eigenbasis
lemmalem:eigenvalues-orthonormal-eigenbasis-2026aAnalysisLinear AlgebraLet together with be a complex inner product space with zero vector . Let be a natural number, let be the initial segment determined by , and let be an -tuple in that is an orthonormal basis of , with comp…Action of an Operator with an Orthonormal Eigenbasis
lemmalem:orthonormal-eigenbasis-action-2026aAnalysisLinear AlgebraLet together with be a complex inner product space with zero vector . Let be a natural number, let be the initial segment determined by , and let be an -tuple in that is an orthonormal basis of , with comp…- Let , , , with rate bound , with derivative bound , , with second-derivative bound , , and be as in the definition of a stationary mean-field triple, let be the…
- Let be a complex vector space, let be a linear operator on , and let be a complex number. The number is an eigenvalue of if there exists a vector that is an eigenvector of with eigenvalue .
- Let and be natural numbers with and . Let be a nonempty subset of Euclidean space , let be a transition-rate family on states with control set and rate bound , let be a…
Joint Measurability of the State and Control of the Controlled N-Agent Dynamics
lemmalem:n-agent-joint-measurability-2026bProbabilityAdopt the setting of the controlled -agent dynamics with agents, states, observation channels, and control dimension , and let be a nonempty subset of Euclidean space : a transition-rate family with control set…Regularity and Derivative Bounds of the Extended Aggregate State Drift
lemmalem:extended-drift-regularity-2026bProbabilityLet and be natural numbers with and , let be a nonempty subset of Euclidean space , let be a transition-rate family on states with control set and rate bound , let be a…Integration by Parts for Indefinite Lebesgue Integrals on a Compact Interval
lemmalem:lebesgue-integration-by-parts-2026bAnalysisLet be a real number, and let be measurable with respect to the trace Borel -algebra on and Lebesgue integrable over . Let and be real numbers and define…Multivariate Taylor Expansion with Uniform Second-Order Remainder
lemmalem:taylor-second-order-uniform-2026bAnalysisLet be a natural number, let be an open subset of Euclidean space, and let be of class on (via clause 3 there); write for the partial derivative with respect to the -th coordinate. Let be…