We study constrained and unconstrained optimization programs for nonconvex maximum eigenvalue functions. We show how second order techniques may be introduced as soon as it is possible to reliably guess the multiplicity of the maximum eigenvalue at a limit point. We examine in which way standard and projected Newton steps may be combined with a nonsmooth first-order method to obtain a globally ...

In this work, we consider block-Jacobi methods with Newton steps in each subspace search and prove their local quadratic convergence to a local minimum with non-degenerate Hessian under some orthogonality assumptions on the search directions. Moreover, such a method is exemplified for non-unitary joint matrix diagonalization, where we present a block-Jacobi-type method on the oblique manifold w...

The dynamics of Steffesen-type methods, using a graphical tool for showing the basins of attraction, is presented. The study includes as particular cases, Steffesen-type modifications of the Newton, the two-steps, the Chebyshev, the Halley and the super– Halley iterative methods. The goal is to show that if we are interesting to preserve the convergence properties we must ensure that the deriva...

We introduce a simple local atomic structure optimization algorithm which is significantly faster than standard implementations of the conjugate gradient method and often competitive with more sophisticated quasi-Newton schemes typically used in ab initio calculations. It is based on conventional molecular dynamics with additional velocity modifications and adaptive time steps. The surprising e...

We propose to find the propagation constants of modes in layered media by means of signal identification methods. To this effect we employ Cauchy’s theorem, conformal mapping and Fast Fourier Transform (FFT) techniques to generate relevant Hankel moments, afterwards to be processed with selected signal identification algorithms. The method, terminated by a few Newton steps, provides a batch of ...

Michael Shub and Steve Smale Abstra t. We estimate the probability that a given number of projective Newton steps applied to a linear homotopy of a system of n homogeneous polynomial equations in n + 1 complex variables of fixed degrees will find all the roots of the system. We also extend the framework of our analysis to cover the classical implicit function theorem and revisit the condition n...

Aims. By measuring the gravitational redshift of spectral features in the spectrum of thermal radiation emitted from neutron stars, useful constraints for the equation of state of superdense matter can be obtained via an estimate of the mass-to-radius ratio. We searched for spectral line features in the high-resolution X-ray spectrum of the isolated neutron star RX J0720.4−3125. Methods. Our ta...

Continuous Markov processes, a well developed field of mathematics [1]–[6], have not yet had their full impact on modern physics. The earliest of these, developed by Einstein [7], Smoluchowski [8], and later refined by Wiener [9] were the original attempts to model diffusion. They did not have a simple phase space interpretation, and as a result were considered unphysical. The Ornstein-Uhlenbec...

This paper presents a novel recursive maximum a posteriori update for the Kalman formulation of undelayed bearing-only SLAM. The estimation update step is cast as an optimization problem for which we can prove the global minimum is reachable via a bidirectional search using Gauss-Newton’s method along a one-dimensional manifold. While the filter is designed for mapping just one landmark, it is ...