Some properties on G-evaluation and its applications to G-martingale decomposition

In this article, a sublinear expectation induced by G-expectation is introduced, which is called G- evaluation for convenience. As an application, we prove that for any ξ∈ L β G (Ω T ) with some β > 1 the martingale decomposition theorem under G-expectaion holds, and that any β > 1 integrable symmetric G-martingale can be represented as an Ito integral w.r.t. G-Brownian motion. As a byproduct, we prove a regularity property for G-martingales: Any G-martingale {M t } has a quasi-continuous version.

A Relationship Between the Conditional g-Evaluation System and the Generator g and Its Applications

In this paper, under the most elementary conditions on a backward stochastic differential equation （BSDE for short） introduced by Peng, a new relationship between the conditional g-evaluation system and the generator g of BSDE is obtained in the sense of ＂process＂, based on some recent results of Jiang. Moreover, as applications, two converse comparison theorems and two uniqueness theorems on the generators of BSDEs are proved.

The Domination of g-evaluations and Choquet Evaluations

In this paper, we obtain that a convex g evaluation can be dominated by the corresponding Choquet evaluation if and only if g has the form g（t, y, z） =uty ＋ h（t, z）, where h（t, z） is positively homogeneous and subadditive with respect to z.

Dynamically Consistent Nonlinear Evaluations with Their Generating Functions in L^p

In this paper, we study dynamically consistent nonlinear evaluations in Lp （1 〈 p 〈 2）. One of our aim is to obtain the following result： under a domination condition, an Ft-consistent evaluation is an Sg-evaluation in Lp. Furthermore, without the assumption that the generating function g（t, w, y, z） is continuous with respect to t, we provide some useful characterizations of an εg-evaluation by g and give some applications. These results include and extend some existing results.

Stochastic ordering by g-expectations

We derive sufficient conditions for the convex and monotonic g-stochastic ordering of diffusion processes under nonlinear g-expectations and g-evaluations.Our approach relies on comparison results for forward-backward stochastic differential equations and on several extensions of convexity,monotonicity,and continuous dependence properties for the solutions of associated semilinear parabolic partial differential equations.Applications to contingent claim price comparison under different hedging portfolio constraints are provided.