Results 61 to 70 of about 20,979 (232)

Flows on rooted trees and the Narayana idempotents [PDF]

, 2012
Several generating series for flows on rooted trees are introduced, as elements in the group of series associated with the Pre-Lie operad. By combinatorial arguments, one proves identities that characterise these series.
Chapoton, Frédéric
core  

A Logratio Approach to the Analysis of Autosomal Genotype Frequencies Across Multiple Samples

Molecular Ecology Resources, Volume 26, Issue 1, January 2026.
ABSTRACT More than 25 years ago, Aitchison showed that the logratio principal component analysis of multiple samples of a biallelic polymorphism can evidentiate the Hardy–Weinberg law. However, hitherto compositional data analysis, that is, the logratio approach, has had little impact in population genetics.
Jan Graffelman
wiley   +1 more source

The Group Inverse of the Combinations of Two Idempotent Operators

Abstract and Applied Analysis, 2013
We present some inverses and group inverses results for linear combinations of two idempotents and their products.
Shunqin Wang, Chunyuan Deng
doaj   +1 more source

Idempotents et échantillonnage parcimonieux [PDF]

Comptes Rendus. Mathématique, 2011
Comment reconstituer un signal, assimilé à une fonction x définie sur le groupe cyclique ZN, quʼon sait porté par T points, en nʼutilisant sa transformée de Fourier xˆ que sur un ensemble Ω de fréquences ? Le procédé indiqué par Candès (2006) [1], Candès, Romberg et Tao (2006) [2] est lʼextrapolation minimale de xˆ|Ω dans Fℓ1.
openaire   +2 more sources

Radical preservation and the finitistic dimension

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We introduce the notion of radical preservation and prove that a radical‐preserving homomorphism of left artinian rings of finite projective dimension with superfluous kernel reflects the finiteness of the little finitistic, big finitistic, and global dimension.
Odysseas Giatagantzidis
wiley   +1 more source

Further results on Left and Right Generalized Drazin Invertible Operators

Математичні Студії, 2020
In this paper we present some new characteristics and expressions of left and right generalized Drazin invertible bounded operators on a Banach space $X.$ An explicit formula relating the left and the right generalized Drazin inverses to spectral ...
So. Messirdi, Sa. Messirdi, B. Messirdi
doaj   +1 more source

Tropical algebra for noise removal and optimal control

Journal of Low Frequency Noise, Vibration and Active Control, 2023
Algorithms for noise removal are either complex or ineffective, and the optimal control with inequality constrains makes the algorithm even more complex.
Chun-Mei Gong, Jiao Peng, Jing Wang
doaj   +1 more source

Rotational Invariance in Resting‐State fMRI: A Geometric Framework for Understanding Signal Processing and Connectivity

Concepts in Magnetic Resonance Part A, Volume 2026, Issue 1, 2026.
Resting‐state functional MRI (rsfMRI) analysis relies on complex mathematical operations whose properties and pitfalls are often poorly understood, leading to interpretational errors and suboptimal processing choices. This work presents novel mathematical insights for rsfMRI analysis through three key contributions: (1) a unified geometric framework ...
Chisondi S. Warioba, Gianluigi Veglia
wiley   +1 more source

Groups having unique faithful irreducible Q-representation

Ratio Mathematica
In this paper, we give few sufficient conditions for finite p-group to have unique NEW (i.e faithful irreducible) Q-representation. As a consequence of these conditions we will prove that any finite p-group of nilpotency class 2 has atmost one NEW Q ...
Vikas Jadhav
doaj   +1 more source

A note on rings which are multiplicatively generated by idempotents and nilpotents

International Journal of Mathematics and Mathematical Sciences, 1988
We give the structure of certain rings which are multiplicatively generated by nilpotents or multiplicatively generated by idempotents and nilpotents.
Hazar Abu-Khuzam
doaj   +1 more source