Ioannis Drakos
Ιωάννης Δράκος Senior Associate Division: Stochastic Analysis & Control Specialization: Stochastic Analysis & Free Boundary ProblemsIoannis Drakos is a Senior Research Associate in the Optimal Policy and Applications Division at the Institute for Advanced Dynamic Uncertainty. He holds a PhD in Mathematics from King's College London (Department of Mathematics), where his doctoral research developed sharp regularity results for the free boundary in a class of optimal stopping problems driven by multidimensional diffusions. His thesis established continuous differentiability of the exercise boundary under general drift and diffusion coefficients, extended the smooth-fit principle to settings with state-dependent volatility and killing rates, and derived the first rigorous local-time decomposition for the value function at the free boundary in problems with non-smooth payoffs.
Drakos's research centres on the fine properties of free boundaries arising in optimal stopping and singular stochastic control: the regularity of the boundary as a function of the model parameters, the rate of convergence of numerical approximations to the true boundary, and the qualitative behaviour of the value function in the vicinity of contact. He has particular interest in problems where the free boundary exhibits non-monotone or disconnected structure — settings in which classical one-dimensional intuition fails and where a genuinely multidimensional stochastic analysis is required. His work draws heavily on potential theory, the theory of excessive functions, and probabilistic representations of solutions to elliptic and parabolic PDEs.
At IADU, his research focuses on free boundary problems embedded in HJB equations for policy optimisation, optimal intervention timing for a regulator facing a controlled diffusion with irreversible state transitions, and the analysis of contact sets in mean field game systems where the equilibrium density develops singular support.
Publications
IADU Publications
Publications forthcoming.
Selected Prior Work
- Continuous differentiability of the free boundary in multidimensional optimal stopping under state-dependent volatility Stochastic Analysis and Applications
- The smooth-fit principle for optimal stopping with killing and state-dependent coefficients Statistics & Probability Letters
- Local-time decompositions at the free boundary for optimal stopping problems with non-smooth payoffs Stochastics
- Non-monotone free boundaries in two-dimensional optimal stopping: structure and numerical approximation Methodology and Computing in Applied Probability
- Excessive functions, potential theory, and the geometry of contact sets in singular control problems Journal of Applied Probability
- Convergence rates for penalisation schemes approximating free boundaries in parabolic obstacle problems Sequential Analysis
Contact
For research enquiries, contact the Institute at research@iadu.org and include I. Drakos in the subject line. All correspondence is handled in accordance with IADU's institutional communication policy.