On vector-valued Hardy martingales and a generalized Jensen's inequality
نویسندگان
چکیده
منابع مشابه
On Vector-valued Hardy Martingales and a Generalized Jensen’s Inequality
We establish a generalized Jensen’s inequality for analytic vector-valued functions on TN using a monotonicity property of vector-valued Hardy martingales. We then discuss how this result extends to functions on a compact abelian group G, which are analytic with respect to an order on the dual group. We also give a generalization of Helson and Lowdenslager’s version of Jensen’s inequality to ce...
متن کاملA large-deviation inequality for vector-valued martingales
Let X = (X0, . . . , Xn) be a discrete-time martingale taking values in any real Euclidean space such that X0 = 0 and for all n, ‖Xn − Xn−1‖ ≤ 1. We prove the large deviation bound Pr [‖Xn‖ ≥ a] < 2e1−(a−1) 2/2n. This upper bound is within a constant factor, e2, of the AzumaHoeffding Inequality for real-valued martingales. This improves an earlier result of O. Kallenberg and R. Sztencel (1992)....
متن کاملBilateral composition operators on vector-valued Hardy spaces
Let $T$ be a bounded operator on the Banach space $X$ and $ph$ be an analytic self-map of the unit disk $Bbb{D}$. We investigate some operator theoretic properties of bilateral composition operator $C_{ph, T}: f ri T circ f circ ph$ on the vector-valued Hardy space $H^p(X)$ for $1 leq p leq +infty$. Compactness and weak compactness of $C_{ph, T}$ on $H^p(X)$ are characterized an...
متن کاملVector–valued Hardy Inequalities and B–convexity
Inequalities of the form ∑∞ k=0 |f̂(mk)| k+1 ≤ C ‖f‖1 for all f ∈ H1, where {mk} are special subsequences of natural numbers, are investigated in the vector-valued setting. It is proved that Hardy’s inequality and the generalized Hardy inequality are equivalent for vector valued Hardy spaces defined in terms of atoms and that they actually characterize B-convexity. It is also shown that for 1 < ...
متن کاملbilateral composition operators on vector-valued hardy spaces
let $t$ be a bounded operator on the banach space $x$ and $ph$ be an analytic self-map of the unit disk $bbb{d}$. we investigate some operator theoretic properties of bilateral composition operator $c_{ph, t}: f ri t circ f circ ph$ on the vector-valued hardy space $h^p(x)$ for $1 leq p leq +infty$. compactness and weak compactness of $c_{ph, t}$ on $h^p(x)$ are characterized an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal of Mathematics and Mathematical Sciences
سال: 2003
ISSN: 0161-1712,1687-0425
DOI: 10.1155/s0161171203206116