Results 91 to 100 of about 14,702 (264)

Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We study the high‐dimensional dynamics of online stochastic gradient descent (SGD) for the multi‐spiked tensor model. This multi‐index model arises from the tensor principal component analysis (PCA) problem with multiple spikes, where the goal is to estimate the unknown signal vectors within the N$N$‐dimensional unit sphere through maximum ...
Gérard Ben Arous, Cédric Gerbelot, Vanessa Piccolo   +2 more
wiley   +1 more source

A note on class numbers of algebraic number fields

Journal of Number Theory, 1969
AbstractIt is proved, by elementary method, that, for a given odd prime number q and a given natural number e, there are infinitely many non-Galois algebraic number fields of degree q over Q, whose class numbers are all divisible by qe.
openaire   +1 more source

Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley   +1 more source

Photometric Diagnostic of the Sheath Dynamics and Electron Density Trends in Single and Dual Frequency CCRF Argon Plasmas

Contributions to Plasma Physics, EarlyView.
ABSTRACT A methodological study is presented on a noninvasive photometric diagnostic for determining trends in electron density and sheath dynamics in single (1f) and a dual (2f) radio frequency capacitively coupled (CCRF) argon plasmas. The 1f discharges are operated at 13.56 and 27.12 MHz, respectively, while the 2f discharge is driven by both ...
Daniel Zuhayra, Jessica Niemann, Viktor Schneider, Holger Kersten   +3 more
wiley   +1 more source

Number-Theoretic Transforms: Theory and Applications in Modern Cryptography

IEEE Access
Number-theoretic transforms (NTT) provide exact arithmetic and efficient convolution over finite algebraic structures, and have emerged as a foundational computational primitive in modern cryptography.
Juliano B. Lima, Jose R. De Oliveira Neto   +1 more
doaj   +1 more source

Review and prospects of shear test of bolted rock joints

Deep Underground Science and Engineering, EarlyView.
The laboratory shear test equipment, test method, and numerical simulation of bolted rock joints were summarized. The shortcomings and limitations of the current research were analyzed, and the research prospects were proposed. Abstract Rock bolting is a critical approach in geotechnical engineering for supporting weak rocks.
Shulin Ren, Fan Yang, Manchao He, Yong Yuan, Zhigang Tao   +4 more
wiley   +1 more source

The number of rational points of some classes of algebraic varieties over finite fields

Open Mathematics
Let Fq{{\mathbb{F}}}_{q} be the finite field of characteristic pp and Fq*=Fq\{0}{{\mathbb{F}}}_{q}^{* }\left={{\mathbb{F}}}_{q}\backslash \left\{0\right\}.
Zhu Guangyan, Fang Yingjue, Luo Yuanyuan, Lin Zongbing   +3 more
doaj   +1 more source

Latitudinal effect on the structure of snake–prey interaction networks is mediated by snake species richness

Ecography, EarlyView.
Despite the growing number of studies on trophic networks in recent decades, there are still important gaps in our understanding of how these networks are structured across broad environmental gradients. These gaps are even greater in some groups of terrestrial vertebrates, such as snakes, requiring a cohesive synthesis of their broader trophic ...
Daniela Pinto‐Coelho, Kate P. Maia, Laura R. V. Alencar, Marcio Martins, Paulo R. Guimarães   +4 more
wiley   +1 more source

Edge‐Based Discretizations on Triangulations in Any Dimension, With Special Attention to Four‐Dimensional Space

International Journal for Numerical Methods in Fluids, EarlyView.
This article provides important geometric formulas for node‐centered, edge‐based schemes in any number of dimensions. These formulas are noteworthy, as they do not require the explicit formation of dual regions. We prove several key geometric results, with a particular focus on the four‐dimensional case, due to potential space‐time applications ...
Nicholas Tufillaro, David M. Williams, Hiroaki Nishikawa   +2 more
wiley   +1 more source

Subspace Acceleration for Efficient Nonlinear Water Wave Simulation

International Journal for Numerical Methods in Fluids, EarlyView.
We introduce an exponentially weighted subspace acceleration technique to reduce GMRES iterations for solving the Poisson equation with time‐dependent coefficients in nonlinear, dispersive free‐surface flows governed by the incompressible Navier‐Stokes equations. The method significantly reduces memory requirements and computational complexity compared
Rasmus Kleist Hørlyck Sørensen, Margherita Guido, Allan Peter Engsig‐Karup, Daniel Kressner   +3 more
wiley   +1 more source