A one-parameter family of operators defined on analytic functions in a circle

Author(s):  
Yûsaku Komatu
2003 ◽  
Vol 13 (03) ◽  
pp. 631-641 ◽  
Author(s):  
PETER ASHWIN ◽  
XIN-CHU FU ◽  
JONATHAN DEANE

In this paper we discuss the packing properties of invariant disks defined by periodic behavior of a model for a bandpass Σ–Δ modulator. The periodically coded regions form a packing of the forward invariant phase space by invariant disks. For this one-parameter family of PWIs, by introducing codings underlying the map operations we give explicit expressions for the centers of the disks by analytic functions of the parameters, and then show that tangencies between disks in the packings are very rare; more precisely they occur on parameter values that are at most countably infinite. We indicate how similar results can be obtained for other plane maps that are piecewise isometries.


Filomat ◽  
2011 ◽  
Vol 25 (4) ◽  
pp. 85-97 ◽  
Author(s):  
S. Naik

In this article, we consider a two parameter family of generalized Ces?ro operators P b,c , Re (b + 1) > Re c > 0, on classical spaces of analytic functions such as Hardy (H p ), BMOA and a- Bloch space (Ba). We Prove that P b,c, Re(b+1)>Re c > 0 is bounded on H p if and only if p ?(0, ?) and on Ba if and only if a ? (1, ?) and unbounded on H ?, BMOA and Ba, a ?(0, 1]. Also we prove that ?-Cesaro operators C? is a bounded operator from the Hardy space H p to the Bergmann space Ap for p ? (0, 1). Thus, we improve some well known results of the literature.


2020 ◽  
Vol 17 (2) ◽  
pp. 256-277
Author(s):  
Ol'ga Veselovska ◽  
Veronika Dostoina

For the derivatives of Chebyshev second-kind polynomials of a complex vafiable, a system of functions biorthogonal with them on closed curves of the complex plane is constructed. Properties of these functions and the conditions of expansion of analytic functions in series in polynomials under consideration are established. The examples of such expansions are given. In addition, we obtain some combinatorial identities of independent interest.


2020 ◽  
Vol 9 (8) ◽  
pp. 5343-5348 ◽  
Author(s):  
T. G. Shaba ◽  
A. A. Ibrahim ◽  
M. F. Oyedotun

Sign in / Sign up

Export Citation Format

Share Document