Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Thinning: Cell Counts of a Poisson Number of Independent Points
lemmalem:poisson-thinning-2026aProbabilityLet be a probability space, the set of natural numbers with , and the set of real numbers. Let be real, let be a random variable with the Poisson distribution with parameter ,…Factorized Joint Probability Mass Function Implies Independence
lemmalem:factorized-pmf-independence-2026aProbabilityLet be a probability space, let be the set of natural numbers with , and let . Let be random variables such that for every and ev…Multinomial Distribution of Cell Counts for Independent Identically Distributed Points
lemmalem:multinomial-cell-counts-2026aProbabilityLet be a probability space, let be the set of natural numbers with , and let . Let be independent random variables, each with the same distribution . Let …- Let be a probability space, let be the set of natural numbers, let be nonempty, and let be an independent family of random variables on it (for this is an independent sequence). Let b…
Sigma-Algebra Generated by Random Variables and Independence of Sigma-Algebras
definitiondef:independence-sigma-algebras-2026aProbabilityLet be a probability space, let be the set of real numbers, and let be the Borel -algebra. Generated -algebra of a family of random variables. Let be a nonempty set and let be a…- Let be a homogeneous Poisson process with rate on a probability space , so that the mean function of is for all , and let be an intensity function with mean function…
Kolmogorov Forward Equations for the Inhomogeneous Poisson Process
theoremthm:kolmogorov-forward-poisson-2026bProbabilityLet be an intensity function with mean function , and let be an inhomogeneous Poisson process with intensity on a probability space . Here denotes the set of natural numbers,…Existence of the Inhomogeneous Poisson Process
theoremthm:existence-inhomogeneous-poisson-2026bProbabilityLet be an intensity function in the sense of Stochastic Process, Independent Increments, and Inhomogeneous Poisson Process, where is the set of real numbers. Then there exist a probability space and an…Stochastic Process, Independent Increments, and Inhomogeneous Poisson Process
definitiondef:inhomogeneous-poisson-process-2026cProbabilityLet be a probability space and let be the real numbers. A stochastic process on is a family of random variables on indexed by the nonnegative real numbers. The process has…- Let be the set of natural numbers and write for the set of nonnegative integers; let be the set of real numbers and the Borel -algebra. We use the factorial for , e…
Moments and Stability of the Standard Normal Distribution
lemmalem:gaussian-stability-2026aProbabilityLet be the set of real numbers and the set of natural numbers. Claim 1. Let be a standard normal random variable on a probability space. Then , , and are integrable, and the expectation and variance satisfy…Existence of Independent Sequences with Prescribed Distributions
theoremthm:existence-independent-sequence-2026aProbabilityLet be a sequence of probability measures on , where is the set of real numbers, is the Borel -algebra, and is the set of natural numbers. Then there exist…Joint Distribution, Expectations, and Block Independence for Independent Random Variables
theoremthm:independent-block-functions-2026aProbabilityThroughout, is a natural number with , is Euclidean space, denotes the real numbers, and the Borel -algebra. Define the -fold product Borel -algebra on iteratively…Smooth Test Function Criterion for Convergence in Distribution
theoremthm:smooth-test-convergence-distribution-2026aAnalysisProbabilityLet and be random variables, not necessarily on a common probability space, and let denote the real numbers. Call a function an admissible test function if is bounded, is a map on…- Let be a random variable on a probability space with distribution , let denote the real numbers, and let be measurable with respect to the Borel -algebra on both sides. Then …
- Let be a sequence of independent and identically distributed random variables on a probability space such that and have finite expectation, and suppose ; write…
The Gaussian Weight Defines a Probability Distribution
theoremthm:gaussian-integral-2026bAnalysisProbabilityLet with the exponential function, let be Lebesgue measure, and for a Borel set let the integral of Lebesgue Integral of a Nonnegative Measurable Function of the measurable function…- Define by , with the exponential function; is continuous (a composition of continuous maps, by Composition of Continuous Euclidean Maps and claim 3 of Basic Properties of the Exponential Function), hence measurable with respect…
Strong Law of Large Numbers under a Fourth Moment Bound
theoremthm:strong-law-large-numbers-fourth-moment-2026aProbabilityLet be a sequence of independent and identically distributed random variables on a probability space such that has finite expectation (hence so do , , and , since for…- Let be a sequence of independent and identically distributed random variables on a probability space such that and have finite expectation, and write . For let…