Results 41 to 50 of about 603 (182)

On the product of Toeplitz and composition operators on Fock-Sobolev spaces

open access: yes四川大学学报. 自然科学版, 2021
We characterize the boundedness of the product of Toeplitz and composition operators for two polynomials symbols on Fock-Sobolev spaces. We also consider the commutativity of Toeplitz and composition operator, and obtain several necessary and sufficient ...
QIN Jie, WANG Xiao-Feng
doaj  

The Mathematical History Behind the Granger–Johansen Representation Theorem

open access: yesOxford Bulletin of Economics and Statistics, Volume 88, Issue 4, Page 587-602, August 2026.
ABSTRACT When can a vector time series that is integrated once (i.e., becomes stationary after taking first differences) be described in error correction form? The answer to this is provided by the Granger–Johansen representation theorem. From a mathematical point of view, the theorem can be viewed as essentially a statement concerning the geometry of ...
Johannes M. Schumacher
wiley   +1 more source

Cointegration in a MIDAS Regression

open access: yesOxford Bulletin of Economics and Statistics, Volume 88, Issue 4, Page 712-725, August 2026.
ABSTRACT Mixed data sampling (MIDAS) cointegration models are used to analyse variables observed at different frequencies. In this paper, we start from an assumed autoregressive distributed lag (ADL) model for high‐frequency observations, and derive the resulting representation when the dependent variable is only observed at a lower frequency.
H. Peter Boswijk, Philip Hans Franses
wiley   +1 more source

A compatibility criterion for optimal control and information aggregation in hierarchical network systems

open access: yesAsian Journal of Control, Volume 28, Issue 4, Page 1722-1733, July 2026.
Abstract Large swarms often adopt a hierarchical network structure that incorporates information aggregation. Although this approach offers significant advantages in terms of communication efficiency and computational complexity, it can also lead to degradation due to information constraints.
Kento Fujita, Daisuke Tsubakino
wiley   +1 more source

ASYMPTOTIC TORSION AND TOEPLITZ OPERATORS [PDF]

open access: yesJournal of the Institute of Mathematics of Jussieu, 2015
We use Toeplitz operators to evaluate the leading term in the asymptotics of the analytic torsion forms associated with a family of flat vector bundles$F_{p}$. For$p\in \mathbf{N}$, the flat vector bundle$F_{p}$is the direct image of$L^{p}$, where$L$is a holomorphic positive line bundle on the fibres of a flat fibration by compact Kähler manifolds. The
Bismut, Jean-Michel   +2 more
openaire   +1 more source

Group Differences of Multiregion Glutamate Concentration in Clinical High Risk and Schizophrenia

open access: yesEuropean Journal of Neuroscience, Volume 64, Issue 1, July 2026.
We investigated group effects of glutamate concentrations in 99 participants in four brain regions using proton magnetic resonance spectroscopy in clinical high risk, schizophrenia spectrum psychotic disorder individuals and healthy controls. Results showed no significant group differences, exploratory analyses showed significant positive symptom ...
Shue Kit Man   +7 more
wiley   +1 more source

Boundedness of Toeplitz type operators associated to Riesz potential operator with general kernel on Orlicz space

open access: yesOpen Mathematics, 2015
In this paper, the boundedness properties for some Toeplitz type operators associated to the Riesz potential and general integral operators from Lebesgue spaces to Orlicz spaces are proved.
Chen Dazhao
doaj   +1 more source

Oxidized MoS2‐Based Multifunctional Memristive Hardware for Energy‐Efficient mmWave Signal Processing and In‐Memory Matrix Multiplication

open access: yesAdvanced Functional Materials, Volume 36, Issue 52, 29 June 2026.
Thermally oxidized MoS2‐based radio‐frequency switches enable a multifunctional platform that unifies broadband RF switching and in‐memory computation. The device achieves a cutoff frequency of 33.2 THz with high energy efficiency and supports hardware‐aware signal processing.
Juho Son   +5 more
wiley   +1 more source

DC Side Impedance Modelling of an Actual Line Commutated Converter High Voltage Direct Current System and DC Resonance Characteristics

open access: yesHigh Voltage, Volume 11, Issue 3, Page 725-737, June 2026.
ABSTRACT The stability analysis of Line Commutated Converter High Voltage Direct Current (LCC‐HVDC) is of considerable engineering importance. Establishing its analytical mathematical model helps to analyse stability and the factors that affect stability of the system.
Juanjuan Wang   +6 more
wiley   +1 more source

Composition operator induced by ?(z) = sz + t for which |s|?1, |t|<1 and |s|+|t|?1

open access: yesمجلة بغداد للعلوم, 2010
We study in this paper the composition operator that is induced by ?(z) = sz + t. We give a characterization of the adjoint of composiotion operators generated by self-maps of the unit ball of form ?(z) = sz + t for which |s|?1, |t|
Baghdad Science Journal
doaj   +1 more source

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