## Abstract (may include machine translation)

In order to be convergent, linear multistep methods must be zero stable. While constant step size theory was established in the 1950’s, zero stability on nonuniform grids is less well understood. Here we investigate zero stability on compact intervals and smooth nonuniform grids. In practical computations, step size control can be implemented using smooth (small) step size changes. The resulting grid {tn}n=0N can be modeled as the image of an equidistant grid under a smooth deformation map, i.e., t_{n}= Φ(τ_{n}) , where τ_{n}= n/ N and the map Φ is monotonically increasing with Φ(0) = 0 and Φ(1) = 1. The model is justified for any fixed order method operating in its asymptotic regime when applied to smooth problems, since the step size is then determined by the (smooth) principal error function which determines Φ, and a tolerance requirement which determines N. Given any strongly stable multistep method, there is an N^{∗} such that the method is zero stable for N> N^{∗}, provided that Φ∈ C^{2}[0 , 1]. Thus zero stability holds on all nonuniform grids such that adjacent step sizes satisfy h_{n}/ h_{n} _{-} _{1}= 1 + O (N^{- 1}) as N→ ∞. The results are exemplified for BDF-type methods.

Original language | English |
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Pages (from-to) | 1125-1143 |

Number of pages | 19 |

Journal | BIT Numerical Mathematics |

Volume | 58 |

Issue number | 4 |

DOIs | |

State | Published - 1 Dec 2018 |

Externally published | Yes |

## Keywords

- BDF methods
- Convergence
- Initial value problems
- Linear multistep methods
- Nonuniform grids
- Variable step size
- Zero stability