We prove a lifting theorem, in the sense of Robinsonian nonstandard analysis, for the G-expectation. Herein, we use an existing discretization theorem for the G-expectation by T. Fadina and F. Herzberg (Bielefeld University, Center for Mathematical Economics in its series Working Papers, 503,...

We refine the discretization of G-expectation by Y. Dolinsky, M.Nutz, and M. Soner (Stochastic Processes and their Applications, 122 (2012), 664-675), in order to obtain a discretization of sublinear expectation where the martingale laws are defined on a finite lattice rather than the whole set...

We study the pricing and hedging of derivative securities with uncertainty about the volatility of the underlying asset. Rather than taking all models from a prespecified class equally seriously, we penalise less plausible ones based on their "distance" to a reference local volatility model. In...

The present paper considers a class of general equilibrium economics when the primitive uncertainty model features uncertainty about continuous-time volatility. This requires a set of mutually singular priors, which do not share the same null sets. For this setting we introduce an appropriate...