Displaying 121 – 140 of 236

Showing per page

On the complexity of sums of Dirichlet measures

Sylvain Kahane (1993)

Annales de l'institut Fourier

Let M be the set of all Dirichlet measures on the unit circle. We prove that M + M is a non Borel analytic set for the weak* topology and that M + M is not norm-closed. More precisely, we prove that there is no weak* Borel set which separates M + M from D (or even L 0 ) , the set of all measures singular with respect to every measure in M . This extends results of Kaufman, Kechris and Lyons about D and H and gives many examples of non Borel analytic sets.

On the duality between p -modulus and probability measures

Luigi Ambrosio, Simone Di Marino, Giuseppe Savaré (2015)

Journal of the European Mathematical Society

Motivated by recent developments on calculus in metric measure spaces ( X , d , m ) , we prove a general duality principle between Fuglede’s notion [15] of p -modulus for families of finite Borel measures in ( X , d ) and probability measures with barycenter in L q ( X , m ) , with q dual exponent of p ( 1 , ) . We apply this general duality principle to study null sets for families of parametric and non-parametric curves in X . In the final part of the paper we provide a new proof, independent of optimal transportation, of the equivalence...

On the extension of measures.

Baltasar Rodríguez-Salinas (2001)

RACSAM

We give necessary and sufficient conditions for a totally ordered by extension family (Ω, Σx, μx)x ∈ X of spaces of probability to have a measure μ which is an extension of all the measures μx. As an application we study when a probability measure on Ω has an extension defined on all the subsets of Ω.

On the extremality of regular extensions of contents and measures

Wolfgang Adamski (1995)

Commentationes Mathematicae Universitatis Carolinae

Let 𝒜 be an algebra and 𝒦 a lattice of subsets of a set X . We show that every content on 𝒜 that can be approximated by 𝒦 in the sense of Marczewski has an extremal extension to a 𝒦 -regular content on the algebra generated by 𝒜 and 𝒦 . Under an additional assumption, we can also prove the existence of extremal regular measure extensions.

Currently displaying 121 – 140 of 236