Results 21 to 30 of about 5,645 (111)

Red Blood Cell Membrane Mechanics Using Discrete Exterior Calculus (DEC) and Optimization

International Journal for Numerical Methods in Biomedical Engineering, Volume 42, Issue 4, April 2026.
We present a novel DEC approach for calculating RBC shapes applicable to other cell types and membrane problems. We derive an energy minimization equation that can be solved semi‐implicitly, and a Lie derivative method to control node spacing. This novel work should aid computational modeling in many biological situations.
Keith C. Afas, Daniel Goldman
wiley   +1 more source

AdS nonlinear instability: moving beyond spherical symmetry

, 2016
Anti-de Sitter (AdS) is conjectured to be nonlinear unstable to a weakly turbulent mechanism that develops a cascade towards high frequencies, leading to black hole formation [1,2].
Dias, Oscar J. C., Santos, Jorge E.
core   +1 more source

Approximation of the Pseudospectral Abscissa via Eigenvalue Perturbation Theory

Numerical Linear Algebra with Applications, Volume 33, Issue 2, April 2026.
ABSTRACT Reliable and efficient computation of the pseudospectral abscissa in the large‐scale setting is still not settled. Unlike the small‐scale setting where there are globally convergent criss‐cross algorithms, all algorithms in the large‐scale setting proposed to date are at best locally convergent.
Waqar Ahmed, Emre Mengi
wiley   +1 more source

Hyperboloidal slices for the wave equation of Kerr-Schild metrics and numerical applications

, 2012
We present new results from two open source codes, using finite differencing and pseudo-spectral methods for the wave equations in (3+1) dimensions. We use a hyperboloidal transformation which allows direct access to null infinity and simplifies the ...
Burko L M, Burko L M, Goodale T Allen G Lanfermann G Massó J Radke T Seidel E Shalf J, Gustafsson B, Jasiulek M, Kreiss H, Michael Jasiulek, Racz I, Rinne O, Schnetter E, Schnetter E, Thornburg J, Tiglio M, Vega I, Wald R M, Zenginoğlu A, Zenginoğlu A, Zenginoğlu A, Zenginoğlu A, Zenginoğlu A Khanna G   +19 more
core   +1 more source

Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the String‐Theoretical Swampland Programme

Fortschritte der Physik, Volume 74, Issue 4, April 2026.
Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley   +1 more source

A minimization principle for the description of time-dependent modes associated with transient instabilities

, 2015
We introduce a minimization formulation for the determination of a finite-dimensional, time-dependent, orthonormal basis that captures directions of the phase space associated with transient instabilities.
Babaee, Hessam, Sapsis, Themistoklis
core   +1 more source

An Effective Physics‐Informed Neural Operator Framework for Predicting Wavefields

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 2, April 2026.
Abstract Solving the wave equation is fundamental for many geophysical applications. However, numerical solutions of the Helmholtz equation face significant computational and memory challenges. Therefore, we introduce a physics‐informed convolutional neural operator (CNO) (PICNO) to solve the Helmholtz equation efficiently.
X. Ma, T. Alkhalifah
wiley   +1 more source

Quantum Dynamical Effects as a Singular Perturbation for Observables in Open Quasi-Classical Nonlinear Mesoscopic Systems

, 2008
We review our results on a mathematical dynamical theory for observables for open many-body quantum nonlinear bosonic systems for a very general class of Hamiltonians.
Berman, Gennady P., Borgonovi, Fausto, Dalvit, Diego A. R.   +2 more
core   +1 more source

Breaking Barriers in High‐Order Spectral Methods: The Intrinsic Matrix Approach

International Journal for Numerical Methods in Engineering, Volume 127, Issue 5, 15 March 2026.
ABSTRACT This paper introduces a unified framework in Hilbert spaces for applying high‐order differential operators in bounded domains using Chebyshev, Legendre, and Fourier spectral methods. By exploiting the banded structure of differentiation matrices and embedding boundary conditions directly into the operator through a scaling law relating ...
Osvaldo Guimarães, José R. C. Piqueira
wiley   +1 more source

Stable Model Reduction for Time‐Domain Room Acoustics: A Structure‐Preserving Formulation for Complex Boundaries

International Journal for Numerical Methods in Engineering, Volume 127, Issue 5, 15 March 2026.
ABSTRACT This work presents novel structure‐preserving formulations for stable model order reduction in the context of time‐domain room acoustics simulations. A solution to address the instability in conventional model order reduction formulations based on the Linearized Euler Equations is derived and validated through numerical experiments.
Satish Bonthu, Hermes Sampedro Llopis, Solvi Thrastarson, Finnur Pind, Runar Unnthorsson   +4 more
wiley   +1 more source