3 papers
math.OC2026
Sphere Constraints and Harmonic Map Flow: Controllability and Reachability by Low-Mode Forcing
Debopriya Mukherjee, Kistosil Fahim, Erika Hausenblas
We study the controllability and reachability of sphere-constrained evolution equations under degenerate (low-mode) forcing, with the harmonic map heat flow as the principal applic…
math.FA2025
Best Approximations on Quasi-Cone Metric Spaces
Ahmad Hisbu Zakiyudin, Kistosil Fahim, Nur Millatul Af-Idah +4
This paper focuses on the best approximation in quasi-cone metric spaces, a combination of quasi-metrics and cone metrics, which generalizes the notion of distance by allowing it t…
math.PR2025
Yamada-Watanabe uniqueness results for SPDEs driven by Wiener and pure jump processes
Kistosil Fahim, Erika Hausenblas, Kenneth H. Karlsen
The Yamada-Watanabe theory provides a robust framework for understanding stochastic equations driven by Wiener processes. Despite its comprehensive treatment in the literature, the…