On some connections between braces and pre-Lie rings outside of the context of Lazard's correspondence
Agata Smoktunowicz
TL;DR
This work develops connections between braces and left-nilpotent pre-Lie rings outside the classical Lazard correspondence. By introducing pullbacks, pseudobraces, and a generalized flow framework using a $ ho^{-1}$-based construction, the authors show that, under Property 1 and 2, the quotient $A/ann(p^{2k})$ of a brace $A$ can be obtained from a pre-Lie ring via a universal formula depending only on the additive group. The main achievement is that factor braces $A/ann(p^{2k})$ are expressible as generalized group-of-flows of left-nilpotent pre-Lie rings, with the $igodot$-operation providing a consistent bridge between brace and pseudobrace realizations. This furnishes a pathway from right-nilpotent braces to broader finite braces and clarifies how pre-Lie structures orchestrate the flow-based construction in a way that is independent of the particular pullback chosen. The results enhance our understanding of radical/flow mechanisms in braces and deepen connections to pre-Lie algebras, Lie theory, and Yang-Baxter-related structures beyond Lazard’s correspondence.
Abstract
Let $p>3$ be a prime number and let $A$ be a brace whose additive group is a direct sum of cyclic groups of cardinalities larger than $p^{α}$ for some $α$. Suppose that either (i) $A^{\lfloor{\frac {p-1}4}\rfloor}\subseteq pA$ or that (ii) the additive group of brace $A$ has rank smaller than ${\lfloor{\frac {p-1}4}\rfloor}$. It is shown that for every natural number $i\leq α- {\frac {4α}{p-1}}$ the factor brace $A/p^{i}A$ is obtained by a formula similar to the group of flows from a left nilpotent pre-Lie ring.
