Dear All, You are kindly invited to attend the next Stochastic and Finance seminar. On Tuesday June 23 at 2pm (Sydney time) Ben Goldys (U Sydney) will give a talk via Zoom. Zoom link:https://uni-sydney.zoom.us/j/7812717331 Meeting ID: 781 271 7331 Speaker: Ben Goldys (U Sydney) Title: G-expectation via Nisio semigroup -- Part 1 Abstract: The concept of G-expectation introduced by Peng takes as its starting point a non-trivial result from the theory of fully nonlinear partial differential equations. I will present another approach to G-expectation based on an old idea of M. Nisio, who introduced a non-linear semigroup corresponding to an optimal control problem. However, the Nisio approach had some some serious limitations. I will present an improvement of her theory, that will allow us to recover some basic properties of G-expectation. The existence of a unique viscosity solution to the corresponding fully nonlinear partial differential equation will follow naturally, in the same way as for the Kolmogorov equations associated to Markov processes. The talk is based on a recent paper by Max Nendel and Michael Roeckner (2019) and on our joint work in preparation. http://www.maths.usyd.edu.au/u/SemConf/Stochastics_Finance/seminar.html Please feel free to forward this message to anyone who might be interested in this talk. Kind regards, Anna