Abstract
We study a conical extension of averaged nonexpansive operators and the role it plays in convergence analysis of fixed point algorithms. Various properties of conically averaged operators are systematically investigated, in particular, the stability under relaxations, convex combinations and compositions. We derive conical averagedness properties of resolvents of generalized monotone operators. These properties are then utilized in order to analyze the convergence of the proximal point algorithm, the forward–backward algorithm, and the adaptive Douglas–Rachford algorithm. Our study unifies, improves and casts new light on recent studies of these topics.
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Acknowledgements
We would like to thank two anonymous referees for their careful review and helpful comments. SB was partially supported by a UMass Lowell faculty startup grant. MND was partially supported by Discovery Projects 160101537 and 190100555 from the Australian Research Council. HMP was partially supported by Autodesk, Inc. via a gift made to the Department of Mathematical Sciences, UMass Lowell.
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Bartz, S., Dao, M.N. & Phan, H.M. Conical averagedness and convergence analysis of fixed point algorithms. J Glob Optim 82, 351–373 (2022). https://doi.org/10.1007/s10898-021-01057-4
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DOI: https://doi.org/10.1007/s10898-021-01057-4
Keywords
- Adaptive Douglas–Rachford algorithm
- Cocoercivity
- Conically averaged operator
- Forward–backward algorithm
- Proximal point algorithm
- Strong monotonicity
- Weak monotonicity