Computing (un) stable manifolds with validated error bounds: non-resonant and resonant spectra

JB van den Berg, JD Mireles James… - Journal of Nonlinear …, 2016 - Springer
We develop techniques for computing the (un) stable manifold at a hyperbolic equilibrium of
an analytic vector field. Our approach is based on the so-called parametrization method for …

Automatic differentiation for Fourier series and the radii polynomial approach

JP Lessard, JDM James, J Ransford - Physica D: Nonlinear Phenomena, 2016 - Elsevier
In this work we develop a computer-assisted technique for proving existence of periodic
solutions of nonlinear differential equations with non-polynomial nonlinearities. We exploit …

Stationary coexistence of hexagons and rolls via rigorous computations

JB van den Berg, A Deschênes, JP Lessard… - SIAM Journal on Applied …, 2015 - SIAM
In this work we introduce a rigorous computational method for finding heteroclinic solutions
of a system of two second order differential equations. These solutions correspond to …

Computation of maximal local (un) stable manifold patches by the parameterization method

M Breden, JP Lessard, JDM James - Indagationes Mathematicae, 2016 - Elsevier
In this work we develop some automatic procedures for computing high order polynomial
expansions of local (un) stable manifolds for equilibria of differential equations. Our method …

A proof of Wright's conjecture

JB van den Berg, J Jaquette - Journal of Differential Equations, 2018 - Elsevier
Wright's conjecture states that the origin is the global attractor for the delay differential
equation y′(t)=− α y (t− 1)[1+ y (t)] for all α∈(0, π 2] when y (t)>− 1. This has been proven to …

Validation of the bifurcation diagram in the 2D Ohta–Kawasaki problem

JB van den Berg, JF Williams - Nonlinearity, 2017 - iopscience.iop.org
We develop a rigorous numerical method to compare local minimizers of the Ohta–
Kawasaki functional in two dimensions. In particular, we validate the phase diagram …

[HTML][HTML] Fourier–Taylor parameterization of unstable manifolds for parabolic partial differential equations: formalism, implementation and rigorous validation

C Reinhardt, JDM James - Indagationes Mathematicae, 2019 - Elsevier
We study polynomial expansions of local unstable manifolds attached to equilibrium
solutions of parabolic partial differential equations. Due to the smoothing properties of …

Numerical computations and computer assisted proofs of periodic orbits of the Kuramoto--Sivashinsky equation

JL Figueras, R de la Llave - SIAM Journal on Applied Dynamical Systems, 2017 - SIAM
We present numerical results and computer assisted proofs of the existence of periodic
orbits for the Kuramoto--Sivashinky equation. These two results are based on writing down …

Spatial periodic orbits in the equilateral circular restricted four-body problem: computer-assisted proofs of existence

J Burgos-García, JP Lessard, JDM James - Celestial Mechanics and …, 2019 - Springer
We use validated numerical methods to prove the existence of spatial periodic orbits in the
equilateral restricted four-body problem. We study each of the vertical Lyapunov families (up …

A framework for the numerical computation and a posteriori verification of invariant objects of evolution equations

JL Figueras, M Gameiro, JP Lessard… - SIAM Journal on Applied …, 2017 - SIAM
We develop a theoretical framework for computer-assisted proofs of the existence of
invariant objects in semilinear PDEs. The invariant objects considered in this paper are …