Results 51 to 60 of about 24,975 (207)

On the Hermitian structures of the sequence of tangent bundles of an affine manifold endowed with a Riemannian metric

Complex Manifolds, 2022
Let (M, ∇, 〈, 〉) be a manifold endowed with a flat torsionless connection r and a Riemannian metric 〈, 〉 and (TkM)k≥1 the sequence of tangent bundles given by TkM = T(Tk−1M) and T1M = TM. We show that, for any k ≥ 1, TkM carries a Hermitian structure (Jk,
Boucetta Mohamed
doaj   +1 more source

Hessian manifolds of constant Hessian sectional curvature

Journal of the Mathematical Society of Japan, 1995
Let \(M\) be a flat affine manifold with a flat affine connection \(D\). If \(M\) admits a Riemannian metric \(g\) such that \(g\) is locally expressed by \(g= D^2 u\), then \((M, D, g)\) is said to be a Hessian manifold. We define Hessian sectional curvatures (these correspond to holomorphic sectional curvatures for Kählerian manifolds) and construct ...
openaire   +3 more sources

Degenerate complex Hessian equations on compact Kahler manifolds [PDF]

Indiana University Mathematics Journal, 2015
Let $(X, )$ be a compact K hler manifold of dimension $n$ and fix $m\in \mathbb{N}$ such that $1\leq m \leq n$. We prove that any $( ,m)$-sh function can be approximated from above by smooth $( ,m)$-sh functions. A potential theory for the complex Hessian equation is also developed which generalizes the classical pluripotential theory on compact K
Lu, Chinh H., Nguyen, Van-Dong
openaire   +2 more sources

Equilibrium Propagation for Dissipative Dynamics

Advanced Intelligent Systems, EarlyView.
This work develops local learning rules for damped linear dynamical systems, including mechanical structures and resistor‐inductor‐capacitor (RLC) circuits, by leveraging an effective action formulation. It demonstrates how physical systems can autonomously compute gradients and learn temporal patterns, enabling applications such as sound ...
Marc Berneman, Daniel Hexner
wiley   +1 more source

ℓ2,1 Norm and Hessian Regularized Non-Negative Matrix Factorization with Discriminability for Data Representation

Applied Sciences, 2017
Matrix factorization based methods have widely been used in data representation. Among them, Non-negative Matrix Factorization (NMF) is a promising technique owing to its psychological and physiological interpretation of spontaneously occurring data.
Peng Luo, Jinye Peng, Jianping Fan
doaj   +1 more source

Contravariant pseudo-Hessian manifolds and their associated Poisson structures [PDF]

Differential Geometry and its Applications, 2020
A contravariant pseudo-Hessian manifold is a manifold $M$ endowed with a pair $(\nabla,h)$ where $\nabla$ is a flat connection and $h$ is a symmetric bivector field satisfying a contravariant Codazzi equation. When $h$ is invertible we recover the known notion of pseudo-Hessian manifold. Contravariant pseudo-Hessian manifolds have properties similar to
Abdelhak Abouqateb, Mohamed Boucetta, Charif Bourzik   +2 more
openaire   +3 more sources

Sodium Tetraazidoaurate(III)—From Na[AuCl4]·2H2O to Na[Au(N3)4] and Beyond One Step at a Time

Chemistry – A European Journal, EarlyView.
Novel sodium chlorido‐/azidoaurate(III) dihydrates Na[AuCl4–x(N3)x]·2H2O (x = 0, 1, 2, 3, 4) provide the first example of a complete series of gradual substitution on tetramer complex anions to be described. Controlled dehydration of Na[Au(N3)4]·2H2O leads to Na[Au(N3)4]·H2O and Na[Au(N3)4], the latter being a highly explosive material.
Mehmet Somer, Joannis Psilitelis, Raul Cardoso‐Gil, Thomas Doert, Franziska Jach, Ayberk Yılmaz, Alexander Ovchinnikov, Yurii Prots, Helge Rosner, Marcus P. Schmidt, Peter Höhn   +10 more
wiley   +1 more source

Hidden symmetries of two-field cosmological models

, 2019
We determine the most general time-independent Noether symmetries of two-field cosmological models with rotationally-invariant scalar manifold metrics.
Anguelova, Lilia, Babalic, Elena Mirela, Lazaroiu, Calin Iuliu   +2 more
core   +1 more source

The Future of Foundation Machine Learning Potentials and DFT in Homogeneous Catalysis: Competition or Synergy?

Chemistry – A European Journal, EarlyView.
Machine‐learning potentials are increasingly taking on the exploratory tasks of homogeneous catalysis, enabling rapid conformer sampling and reaction‐space mapping. However, when selectivity depends on subtle electronic effects, electronic‐structure methods remain essential.
Maxime Ferrer, Julen Munarriz, Thijs Stuyver, Ruben Laplaza   +3 more
wiley   +1 more source

Optimal model‐based design of experiments for parameter precision: Supercritical extraction case

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract This study investigates the process of chamomile oil extraction from flowers. A parameter‐distributed model consisting of a set of partial differential equations is used to describe the governing mass transfer phenomena in a cylindrical packed bed with solid chamomile particles under supercritical conditions using carbon dioxide as a solvent ...
Oliwer Sliczniuk, Pekka Oinas
wiley   +1 more source