Explicit limiting measures for higher-dimensional penalisation

Identify explicit limiting measures governing penalisation limits for diffusion processes and discrete-time Markov chains in dimensions two and higher, extending the explicit two-dimensional Brownian-motion construction.

Background

The paper establishes penalisation limits for a class of nonnegative, adapted, decreasing functionals of two-dimensional Brownian motion that become constant after the path exits a bounded region. Its analysis relies on a specific path decomposition at the last exit from a circle and on the associated universal sigma-finite measure W(2)\mathbf{W}^{(2)}.

The authors note that, although the general penalisation framework of Najnudel, Roynette, and Yor applies broadly, explicit identification of the limiting measures remains unresolved for diffusion processes and discrete-time Markov chains in dimensions two and higher. Solving this problem would extend the explicit planar Brownian-motion theory to substantially broader stochastic-process settings.

References

While the general penalisation framework developed by Najnudel, Roynette, and Yor applies in considerable generality, the identification of explicit limiting measures in dimension two and higher remains largely open for diffusion processes and discrete-time Markov chains.

Penalisation of Two-Dimensional Brownian Motion  (2608.19396 - Najnudel et al., 19 Aug 2026) in Section 'Further direction of research' (Discussion)