In mathematical set theory, an Ulam matrix is an array of subsets of a cardinal number with certain properties. Ulam matrices were introduced by Stanislaw Ulam in his 1930 work on measurable cardinals: they may be used, for example, to show that a real-valued measurable cardinal is weakly inaccessible. [1]
Suppose that κ and λ are cardinal numbers, and let be a -complete filter on . An Ulam matrix is a collection of subsets of indexed by such that
In mathematical set theory, an Ulam matrix is an array of subsets of a cardinal number with certain properties. Ulam matrices were introduced by Stanislaw Ulam in his 1930 work on measurable cardinals: they may be used, for example, to show that a real-valued measurable cardinal is weakly inaccessible. [1]
Suppose that κ and λ are cardinal numbers, and let be a -complete filter on . An Ulam matrix is a collection of subsets of indexed by such that