We prove an existence of a unique solution of an exponential martingale equation in the class of BMO martingales. The solution is used to characterize optimal martingale measures.

A dx. Given a Banach space (X, ‖ · ‖) and 1 ≤ p < ∞ we shall denote by L(R, X) the space of Bochner p-integrable functions endowed with the norm ‖f‖Lp(Rn,X) = ( ∫ Rn ‖f(x)‖ dx), by Lc (R , X) the closure of the compactly supported functions in L(R, X) and by Lweak,α(R , X) the space of measurable functions such that |{x ∈ R : ‖f(x)‖ > λ}| ≤ α(λ) where α : R → R is a non increasing function. We ...

This paper deals with a BMO theorem for-distorted diffeomorphisms on ‫ޒ‬ D and an application comparing manifolds of speech and sound.

First, we prove that the BMO condition by John–Nirenberg leads in natural way to asymptotic homogeneity at origin of regular homeomorphic solutions degenerate Beltrami equations. Then, on this basis establish a series criteria for existence equations whole complex plane with infinity. These results can be applied fluid mechanics strongly anisotropic and inhomogeneous media because equation is f...

Time consistency is a crucial property for dynamic risk measures. Making use of the dual representation for conditional risk measures, we characterize the time consistency by a cocycle condition for the minimal penalty function. Taking advantage of this cocycle condition, we introduce a new methodology for the construction of time-consistent dynamic risk measures. Starting with BMOmartingales, ...

Let dγ(x) ≡ πe 2 dx for all x ∈ R be the Gauss measure on R. In this paper, the authors establish the characterizations of the space BMO(γ) of Mauceri and Meda via commutators of either local fractional integral operators or local fractional maximal operators. To this end, the authors first prove that such a local fractional integral operator of order β is bounded from L(γ) to L(γ), or from the...

The main purpose of this paper is two-fold. On one hand, we prove a sharper covering lemma in Euclidean space Rn for all n ≥ 2 (see Theorem 1.5). On the other hand, we apply this covering lemma to improve existing results for BMO and volume estimates of nodal sets for eigenfunctions u satisfying 4u + λu = 0 on n-dimensional Riemannian manifolds when λ is large (see Theorems 1.7, 1.8). We also i...