We present an algorithm for reducing the computational work involved in coupled-cluster (CC) calculations by sparsifying the amplitude correction within a CC amplitude update procedure. We provide a theoretical justification for this approach, which is based on the convergence theory of inexact Newton iterations. We demonstrate by numerical examples that, in the simplest case of the CCD equatio...

We present a parallel Newton-Krylov algorithm for solving the three-dimensional Euler equations on multi-block structured meshes. The Euler equations are discretized on each block independently using second-order accurate summation-by-parts operators and scalar numerical dissipation. Boundary conditions are imposed and block interfaces are coupled using simultaneous approximation terms (SATs). ...

Newton-type methods and quasi-Newton methods have proven to be very successful in solving dense unconstrained optimization problems. Recently there has been considerable interest in extending these methods to solving large problems when the Hessian matrix has a known a priori sparsity pattern, This paper treats sparse quasi-Newton methods in a uniform fashion and shows the effect of loss of pos...

This paper presents a simple and computationally-efficient algorithm for solving steady two-dimensional subsonic and transonic compressible flow over an airfoil. This work uses an interactive viscous-inviscid solution by incorporating the viscous effects in a thin shear-layer. Boundary-layer approximation reduces the Navier-Stokes equations to a parabolic set of coupled, non-linear partial diff...

A coupled elastoplastic-damage constitutive model taking into account chemo-induced elastoplastic-damage effects for the modeling of coupled chemothermo-hygro-mechanical behavior of concretes at high temperature is proposed in this article. A three-step operator split algorithm for the integration of the rate coupled constitutive equations is developed. Consistent tangent modulus matrices for c...

The modiied Newton-Sabatier method is extended to the inverse scattering problem of coupled channels at xed energy. The problem is solved for a system of coupled radial Schrr odinger equations with a potential matrix independent of the angular momentum of the relative motion. The new method is applied to the example of two channels coupled by complex-valued square well potentials. 1 Introductio...

More than a decade agao, Newton’s method has been proposed for constructing the convex best interpolant. Its local quadratic convergence has only been established recently by recasting it as the generalized Newton method for semismooth equations. It still remains mysterious that the Newton method coupled with line search strategies works practically well in global sense. Similar to the classica...

Cartan’s spacetime reformulation of the Newtonian theory of gravity is a generallycovariant Galilean-relativistic limit-form of Einstein’s theory of gravity known as the Newton-Cartan theory. According to this theory, space is flat, time is absolute with instantaneous causal influences, and the degenerate ‘metric’ structure of spacetime remains fixed with two mutually orthogonal non-dynamical m...