A lower bound in Nehari’s theorem on the polydisc

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A Lower Bound in Nehari’s Theorem on the Polydisc

By theorems of Ferguson and Lacey (d = 2) and Lacey and Terwilleger (d > 2), Nehari’s theorem is known to hold on the polydisc D for d > 1, i.e., if Hψ is a bounded Hankel form on H(D) with analytic symbol ψ, then there is a function φ in L∞(Td) such that ψ is the Riesz projection of φ. A method proposed in Helson’s last paper is used to show that the constant Cd in the estimate ‖φ‖∞ ≤ Cd‖Hψ‖ g...

متن کامل

A Lower Bound Theorem

Motivated by Candes and Donoho′s work (Candés, E J, Donoho, D L, Recovering edges in ill-posed inverse problems: optimality of curvelet frames. Ann. Stat. 30, 784-842 (2002)), this paper is devoted to giving a lower bound of minimax mean square errors for Riesz fractional integration transforms and Bessel transforms.

متن کامل

The //"-corona Theorem for the Polydisc

Let Hp = Hp(D") denote the usual Hardy spaces on the polydisc D" . We prove in this paper the following theorem: Suppose f\, fa, ... , fit € H°° , \\fj\\Hoo <\,and Y.%\ \fj(z)\ > S > 0. Then for every g in HP , 1 < p < oo, there are Hp functions g, g, ... , gm such that 2~2T=\ fj(z)Sj(z) = g(z). Moreover, we have ||g/||//p < c(m, n, S , p)\\g\\np . (When p = 2, n = 1 , this theorem is known to ...

متن کامل

An Improved Lower Bound for Folkman’s Theorem

Folkman’s theorem asserts that for each k ∈ N, there exists a natural number n = F (k) such that whenever the elements of [n] are two-coloured, there exists a set A ⊂ [n] of size k with the property that all the sums of the form ∑ x∈B x, where B is a nonempty subset of A, are contained in [n] and have the same colour. In 1989, Erdős and Spencer showed that F (k) ≥ 2ck2/ log , where c > 0 is an ...

متن کامل

Razborov Disjointness Lower Bound , Forster ’ S Theorem

In this lecture, we show two results dealing with lower bounds in communication complexity. The first lower bound is an Ω(n) lower bound on the distributional complexity of Disjointness due to [3, 8]. Here we will present the simplified proof presented in [8]. In the second part, we will show how to obtain lower bounds on the unbounded error probabilistic communication complexity by Forster’s m...

متن کامل

ذخیره 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: Journal d'Analyse Mathématique

سال: 2012

ISSN: 0021-7670,1565-8538

DOI: 10.1007/s11854-012-0038-y