Let $varphi(z)=z^m, z in mathbb{U}$, for some positive integer $m$, and $C_varphi$ be the composition operator on the Bergman space $mathcal{A}^2$ induced by $varphi$. In this article, we completely determine the point spectrum, spectrum, essential spectrum, and essential norm of the operators $C^*_varphi C_varphi, C_varphi C^*_varphi$ as well as self-commutator and anti-self-commutators of $C_...

‎In this paper we investigate the dilations of completely positive definite representations‎ ‎of (C^ast)-dynamical systems with abelian groups on Hilbert (C^ast)-modules‎. ‎We show that if ((mathcal{A}‎, ‎G,alpha)) is a (C^ast)-dynamical system with (G) an abelian group‎, ‎then every completely positive definite covariant representation ((pi,varphi,E)) of ((mathcal{A}‎, ‎G,alpha)) on a Hilbert ...

We put forward a new general iterative process. We prove a convergence result as well as a stability result regarding this new iterative process for weak contraction operators.

We construct quasi-one-dimensional topological and nontopological three-band lattices with a tunable band gap winding number of the flat band. Using full multiband mean field (MF) exact density matrix renormalization group (DMRG) calculations, we show explicitly how affects pairing superconductivity (SC) in Hubbard model attractive interactions. obtain excellent agreement between MF DMRG calcul...

Cyclic weak φ-contraction mapping is introduced in Menger space and fixed point theorem for such mappings are studied in Menger space. Mathematics Subject Classification 47H10, 54H25

THE VISCOSITY OF A COMPRESSED GAS IS A FUNCTION OF THREE VARIABLES: (1) the degree of crowding of the molecules; (2) their capacity, by reason of softness, flexibility, or rotational inertia, to absorb the vector momentum applied to cause flow; (3) the resistance to this vector momentum offered by the randomly oriented thermal momenta, which becomes significant when the liquid expands sufficien...

Elementary smooth functions (beyond contact) are employed to construct pair correlation functions that mimic jammed disordered sphere packings. Using the g_{2} -invariant optimization method of Torquato and Stillinger [J. Phys. Chem. B 106, 8354 (2002)], parameters in these functions are optimized under necessary realizability conditions to maximize the packing fraction varphi and average numbe...

In this paper, we give some new coupled common  fixed point theorems for probabilistic $varphi$-contractions  in Menger probabilistic metric spaces.  As applications of the main results, we obtain some coupled common fixed point theorems in usual metric spaces and fuzzy metric spaces. The main results of this paper improvethe corresponding results given by some authors. Finally, we give one exa...

The effect of elevated CO(2) and O(3) on apparent quantum yield (varphi), maximum photosynthesis (P(max)), carboxylation efficiency (V(cmax)) and electron transport capacity (J(max)) at different canopy locations was studied in two aspen (Populus tremuloides) clones of contrasting O(3) tolerance. Local light climate at every leaf was characterized as fraction of above-canopy photosynthetic phot...