A contractive Hardy-Littlewood inequality

We prove a contractive Hardy-Littlewood type inequality for functions from $H^p(\mathbb{T})$, $0 < p \le 2$ which is sharp in the first two Taylor coefficients and asymptotically at infinity.Comment: 8 page

Contractive projections in Paley-Wiener spaces

Let $S_1$ and $S_2$ be disjoint finite unions of parallelepipeds. We describe necessary and sufficient conditions on the sets $S_1,S_2$ and exponents $p$ such that the canonical projection $P$ from $PW_{S_1\cup S_2}^p$ to $PW_{S_1}^p$ is a contraction

Completeness of Certain Exponential Systems and Zeros of Lacunary Polynomials

Let $\Gamma$ be a subset of $\{0,1,2,...\}$. We show that if $\Gamma$ has `gaps' then the completeness and frame properties of the system $\{t^ke^{2\pi i nt}: n\in\mathbb{Z},k\in\Gamma\}$ differ from those of the classical exponential systems. This phenomenon is closely connected with the existence of certain uniqueness sets for lacunary polynomials.Comment: 16 pages, 1 figur

Monotonicity theorem for subharmonic functions on manifolds

We provide a sharp monotonicity theorem about the distribution of subharmonic functions on manifolds, which can be regarded as a new, measure theoretic form of the uncertainty principle. As an illustration of the scope of this result, we deduce contractivity estimates for analytic functions on the Riemann sphere, the complex plane and the Poincar\'e disc, with a complete description of the extremal functions, hence providing a unified and illuminating perspective of a number of results and conjectures on this subject, in particular on the Wehrl entropy conjecture by Lieb and Solovej. In this connection, we completely prove that conjecture for SU(2), by showing that the corresponding extremals are only the coherent states. Also, we show that the above (global) estimates admit a local counterpart and in all cases we characterize also the extremal subsets, among those of fixed assigned measure

Nucleus-nucleus interactions in very-high-energy cosmic ray experiments

A review of unusual results of experiments in cosmic rays which cannot be explained in the frame of the existing models of hadron interactions is presented. Requirements to features of a new model which are necessary for explanation of all observed unusual events and phenomena are formulated. A model of hadron interactions with production of QGM blobs with large orbital momentum is considered. Its possibilities for explanation of various unusual events and phenomena are discussed

Fourier Interpolation and Time-Frequency Localization

We prove that under very mild conditions for any interpolation formula f(x)=∑λ∈Λf(λ)aλ(x)+∑μ∈Mf^(μ)bμ(x) we have a lower bound for the counting functions nΛ(R1)+nM(R2)≥4R1R2−Clog2(4R1R2) which very closely matches recent interpolation formulas of Radchenko and Viazovska and of Bondarenko, Radchenko and Seip

Exponential lower bound for the eigenvalues of the time-frequency localization operator before the plunge region

We prove that the eigenvalues $\lambda_n(c)$ of the time-frequency localization operator satisfy $\lambda_n(c) > 1 - \delta^c$ for $n = [(1-\varepsilon)c]$, where $\delta = \delta(\varepsilon) < 1$ and $\varepsilon > 0$ is arbitrary, improving on the result of Bonami, Jaming and Karoui, who proved it for $\varepsilon \ge 0.42$. The proof is based on the properties of the Bargmann transform.Comment: 13 page