All two-dimensional expanding Ricci solitons

Luke T. Peachey; Peter M. Topping

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arXiv · 2307.05306

All two-dimensional expanding Ricci solitons

Luke T. Peachey·Peter M. Topping

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Abstract

The second author and H. Yin have developed a Ricci flow existence theory that gives a complete Ricci flow starting with a surface equipped with a conformal structure and a nonatomic Radon measure as a volume measure. This led to the discovery of a large array of new expanding Ricci solitons. In this paper we use the recent uniqueness theory in this context, also developed by the second author and H. Yin, to give a complete classification of all expanding Ricci solitons on surfaces. Along the way, we prove a converse to the existence theory that is not constrained to solitons: every complete Ricci flow on a surface over a time interval $(0,\varepsilon)$ admits a $t\downarrow 0$ limit within the class of admissible initial data. This makes surfaces the first nontrivial setting for Ricci flow in which a bijection can be given between the entire set of complete Ricci flows over maximal time intervals $(0,T)$, and a class of initial data that induces them.

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Luke T. Peachey, Peter M. Topping. 2023-07-11. All two-dimensional expanding Ricci solitons. https://arxiv.org/abs/2307.05306

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