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May 4, 2019 at 16:01 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Apr 4, 2019 at 15:49 answer added Siddhartha timeline score: 1
Apr 1, 2019 at 8:03 comment added Duchamp Gérard H. E. Maybe it is erroneous because in free Lie rings, we don't have the identity $[[X,Y],[Z,T]]$ equals $[X,Y],Z],T]]]$. In fact, to construct the Dynkin projector, the crucial step is to show that $w\to [w]$ is a derivation of $Li_\mathbb{Z}(X)$ where $X$ is an alphabet and $Li_\mathbb{Z}(X)(\subset \mathbb{Z}<X>)$ the module of Lie polynomials.
Mar 31, 2019 at 20:06 comment added YCor "left-normed": $[x_1,\dots,x_k]=[[x_1,\dots,x_{k-1}],x_k]$.
Mar 31, 2019 at 19:41 comment added Siddhartha It is left normed.
Mar 31, 2019 at 19:24 comment added YCor Maybe also recall the convention for multiple brackets: $[x_1,\dots,x_k]$ is defined as $[x_1,[x_2,\dots,x_k]]$ or as $[[x_1,\dots,x_{k-1}],x_k]$?
Mar 31, 2019 at 19:23 comment added Siddhartha Not really. Let's assume $A$ is non-unital for time being.
Mar 31, 2019 at 19:22 comment added YCor OK; I now get the definition (technically I don't know if you assume $A$ unital, in which case you have to define $\delta(1)$, probably by $\delta(1)=0$; anyway this does not matter for the question).
Mar 31, 2019 at 19:20 history edited YCor
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Mar 31, 2019 at 19:20 comment added Siddhartha Thanks. Edited now.
Mar 31, 2019 at 19:20 history edited Siddhartha CC BY-SA 4.0
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Mar 31, 2019 at 19:19 comment added YCor So it's just "associative monomials", nothing Lie.
Mar 31, 2019 at 19:18 comment added Siddhartha Products of the form $x_{i_1} \dotsc x_{i_m}$ where the variables need not be commutative, but these are associative.
Mar 31, 2019 at 19:17 comment added YCor What do you mean by "associative Lie monomials"?
Mar 31, 2019 at 19:15 history edited Siddhartha CC BY-SA 4.0
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Mar 31, 2019 at 19:08 history edited YCor
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Mar 31, 2019 at 19:07 comment added YCor I have no idea how you define $\delta$, and even how it is supposed to be an operator from which space to which other space (maybe the free Lie ring to itself).
Mar 31, 2019 at 19:00 history asked Siddhartha CC BY-SA 4.0