Group gradings on simple Lie algebras in positive characteristic.

In this paper we describe all gradings by a finite abelian group $G$ on the following Lie algebras over an algebraically closed field $F$ of characteristic $pneq 2$: $mathfrak {sl}_n(F)$ ($n$ not divisible by $p$), $mathfrak {so}_n(F)$ ($ngeq 5$, $nneq 8$) and $mathfrak {sp}_n(F)$ ($ngeq 6$, $n$ even). [ABSTRACT FROM AUTHOR]