{ "id": "1607.00616", "version": "v1", "published": "2016-07-03T08:54:47.000Z", "updated": "2016-07-03T08:54:47.000Z", "title": "Properties of $G$-martingales with finite variation and the application to $G$-Sobolev spaces", "authors": [ "Yongsheng Song" ], "categories": [ "math.PR" ], "abstract": "As is known, a process of form $\\int_0^t\\eta_sd\\langle B\\rangle_s-\\int_0^t2G(\\eta_s)ds$, $\\eta\\in M^1_G(0,T)$, is a non-increasing $G$-martingale. In this paper, we shall show that a non-increasing $G$-martingale could not be form of $\\int_0^t\\eta_sds$ or $\\int_0^t\\gamma_sd\\langle B\\rangle_s$, $\\eta, \\gamma \\in M^1_G(0,T)$, which implies that the decomposition for generalized $G$-It\\^o processes is unique: For $\\zeta\\in H^1_G(0,T)$, $\\eta\\in M^1_G(0,T)$ and non-increasing $G$-martingales $K, L$, if \\[\\int_0^t\\zeta_s dB_s+\\int_0^t\\eta_sds+K_t=L_t,\\ t\\in[0,T],\\] then we have $\\eta\\equiv0$, $\\zeta\\equiv0$ and $K_t=L_t$. As an application, we give a characterization to the $G$-Sobolev spaces introduced in Peng and Song (2015).", "revisions": [ { "version": "v1", "updated": "2016-07-03T08:54:47.000Z" } ], "analyses": { "subjects": [ "60G44", "60G45", "60G48" ], "keywords": [ "sobolev spaces", "finite variation", "martingale", "application" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }