Results 51 to 60 of about 4,239 (245)

Essential Norms of Stević–Sharma Operators from General Banach Spaces into Zygmund-Type Spaces

Journal of Mathematics, 2022
A Stević–Sharma operator denoted by Tψ1,ψ2,φ is a generalization product of multiplication, differentiation, and composition operators. Using several restrictive terms, we characterize an approximation of the essential norm of the Stević–Sharma operator ...
M. A. Bakhit
doaj   +1 more source

Weighted Hardy Spaces on the Unit Disk [PDF]

Complex Analysis and Operator Theory, 2014
In this paper we mainly discuss three things. First, there is no canonical norm on the space $H^p_u(\mathbb{D})$. Second, we improve the weak-$*$ convergence of the measures $ _{u,r}$. Third, the dilations $f_t$ of the function $f\in H^p_u(\mathbb{D})$ converge to $f$ in $H^p_u$-norm and hence the polynomials are dense in $H^p_u(\mathbb{D})$.
openaire   +3 more sources

Controlling the Field: Memory, Labor, and Ethics in Oral Histories of Brazilian Human Genetics

Berichte zur Wissenschaftsgeschichte, EarlyView.
This article examines how oral histories of twentieth‐century human genetics in Brazil reveal the politics of memory of fieldwork. Through a comparative analysis of interviews with prominent geneticist Francisco M. Salzano and technician Girley V. Simões, who worked with him for most of his career, this study explores the narrative strategies each ...
Rosanna Dent, Ana Carolina Vimieiro Gomes   +1 more
wiley   +1 more source

On the Norm of Certain Weighted Composition Operators on the Hardy Space

Abstract and Applied Analysis, 2009
We obtain a representation for the norm of certain compact weighted composition operator 𝐶𝜓,𝜑 on the Hardy space 𝐻2, whenever 𝜑(𝑧)=𝑎𝑧+𝑏 and 𝜓(𝑧)=𝑎𝑧−𝑏. We also estimate the norm and essential norm of a class of noncompact weighted composition operators ...
M. Haji Shaabani, B. Khani Robati
doaj   +1 more source

The flexible, the stereotyped and the in‐between: putting together the combinatory tool use origins hypothesis

Biological Reviews, EarlyView.
ABSTRACT Tool use research has long made the distinction between tool using that is considered learned and flexible, and that which appears to be instinctive and stereotyped. However, animals with an inherited tool use specialisation can exhibit flexibility, while tool use that is spontaneously innovated can be limited in its expression and facilitated
Jennifer A. D. Colbourne, Alice M. I. Auersperg   +1 more
wiley   +1 more source

Local Search and the Evolution of World Models

Topics in Cognitive Science, EarlyView., 2023
Abstract An open question regarding how people develop their models of the world is how new candidates are generated for consideration out of infinitely many possibilities. We discuss the role that evolutionary mechanisms play in this process. Specifically, we argue that when it comes to developing a global world model, innovation is necessarily ...
Neil R. Bramley, Bonan Zhao, Tadeg Quillien, Christopher G. Lucas   +3 more
wiley   +1 more source

Weighted Lorentz Spaces and the Hardy Operator

Journal of Functional Analysis, 1993
The authors find a new expression for the norm of a function in the weighted Lorentz space, with respect to the distribution function, and obtain as simple consequence a generalization of the classical embeddings \(L^{p,1}\subset\cdots\subset L^ p\subset\cdots\subset L^{p,t}\) and a new definition of the weak space \(\Lambda^{p,t}_ u(w)\).
Carro, M.J., Soria, J.
openaire   +2 more sources

Subuniformity of harmonic mean p$$ p $$‐values

Canadian Journal of Statistics, EarlyView.
Abstract We obtain several inequalities on the generalized means of dependent p$$ p $$‐values. In particular, the weighted harmonic mean of p$$ p $$‐values is strictly subuniform under several dependence assumptions of p$$ p $$‐values, including independence, negative upper orthant dependence, the class of extremal mixture copulas, and some Clayton ...
Yuyu Chen, Ruodu Wang, Yuming Wang, Wenhao Zhu   +3 more
wiley   +1 more source

An assessment of stress and production rate of sucker rod heat pipes in oil well pumping system

Deep Underground Science and Engineering, EarlyView.
The sucker rod pumping system is the preferred oil extraction technique. The concept about equipping the hollow vacuum space in solid sucker rods with heat pipe has been scrutinized in terms of stress and oil production evaluation. Abstract The implementation of the heat pipe concept in sucker rods for oil pumping systems negates the requirement for an
R. S. Anand, Ang Li, Wenbo Huang, Juanwen Chen, Qingshan Ma, Fangming Jiang   +5 more
wiley   +1 more source

Boundedness for Commutators of Singular Integral Operator With Weaker Smooth Kernel on Weighted Hardy and Herz Spaces

Journal of Function Spaces
In this job, let T be a variant of Hörmander’s singular operator and b∈Lipβ,ωℝn. We adopt the classic Harmonic analysis method and obtain that commutators are bounded on weighted Hardy space and weighted Herz space.
Jiamei Chen, Jie Sun
doaj   +1 more source