Opuscula Mathematica (Feb 2024)

Finitely additive functions in measure theory and applications

  • Daniel Alpay,
  • Palle Jorgensen

DOI
https://doi.org/10.7494/OpMath.2024.44.3.323
Journal volume & issue
Vol. 44, no. 3
pp. 323 – 339

Abstract

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In this paper, we consider, and make precise, a certain extension of the Radon-Nikodym derivative operator, to functions which are additive, but not necessarily sigma-additive, on a subset of a given sigma-algebra. We give applications to probability theory; in particular, to the study of \(\mu\)-Brownian motion, to stochastic calculus via generalized Itô-integrals, and their adjoints (in the form of generalized stochastic derivatives), to systems of transition probability operators indexed by families of measures \(\mu\), and to adjoints of composition operators.

Keywords