MathGloss

Let (X1,Σ1,μ1)(X_1,\Sigma_1,\mu_1) and (X2,Σ2,μ2)(X_2,\Sigma_2,\mu_2) be two measure spaces, and let Σ1Σ2\Sigma_1\otimes \Sigma_2 be the σ-algebra generated by sets of the form B1×B2B_1\times B_2 for B1Σ1B_1\in \Sigma_1, B2Σ2B_2\in \Sigma_2. A product measure μ1×μ2\mu_1\times \mu_2 is a measure on the measurable space (X1×X2,Σ1Σ2)(X_1\times X_2, \Sigma_1\otimes\Sigma_2) such that (μ1×μ2)(B1×B2)=μ1(B1)μ2(B2)(\mu_1\times\mu_2)(B_1\times B_2) = \mu_1(B_1)\mu_2(B_2) for all B1Σ1B_1\in \Sigma_1, B2Σ2B_2\in \Sigma_2.

Wikidata ID: Q1572094