$\DeclareMathOperator\Div{Div}$Edit: The correct formulation of the vector space $S(X)$ which is defined in this question is the following:$$S(X)=\{Y\in \chi^{\infty}(M)\mid X.\omega(X,Y)=(1/n)Div(X)\omega(X,Y)\}$$.$$S(X)=\{Y\in \chi^{\infty}(M)\mid X.\omega(X,Y)=(1/n)\Div(X)\omega(X,Y)\}.$$ This mistake (typos)had been occurred in remark 6, page 7 of this note, too:
https://arxiv.org/pdf/math/0409594.pdfTaghavi - On periodic solutions of Liénard equations.
Let $(M,\omega)$ be a $2n$ dimensional symplectic manifold and $X$ is a smooth vector field on $M$. Consider the following subvector space of $\chi^{\infty}(M)$: $$S(X)=\{Y\in \chi^{\infty}(M)\mid X.\omega(X,Y)=nDiv(X)\omega(X,Y)\}$$$$S(X)=\{Y\in \chi^{\infty}(M)\mid X.\omega(X,Y)=n\Div(X)\omega(X,Y)\}.$$ Here $Div$$\Div$ is the divergence correspond corresponding to the volum volume form $\omega^{n}$
This vector space contains the Lie algebra $C(X)=\{Y\in \chi^{\infty}(M)\mid [X,Y]=0\}$. It also contains the Lie algebra $M(X)=\{fX\mid f\in C^{\infty}(M)\}$.
Note that, according to the above definition of $S(X)$, the inclusion $C(X)\subset S(X)$ sensitivly sensitively depends on the scalar $n$. If we replace $n$ by another scalar, this inclusion is no longer true. ( NeverthelessNevertheless the inclusion $M(X)\subset S(X)$ is not sensitive to this scalar, that is, it is valid for every other scalar.)
Questions:
What other interesting Lie algebras are contained in $S(X)$?
Is $S(X)$ a Lie subalgebra of $\chi^{\infty}(M)$? If the answer is yes, what are some interesting ideals of $S(X)$? If the answer is no, is the Lie algebra generated by $S(X)$ equal to the lieLie algebra generated by $C(X)$ and $M(X)$?
Motivated by the usual dynamical question "Is the triviality of centralizer a generic situation?", we ask that: Is it true to say that for a generic vector field $X$ we have $S(X)=M(X)$?
Note: At the international workshop on dynamical system in ICTP, Italy, 2001, I hearedheard from a specialist of dynamical system that "However the"the centralizer problem has various aspects both in discretdiscrete and continuous dynamics, but I think that the symplectic version of this problem is interesting and unknown". So this my post is a try for a possible symplectization of "centralizer problem".