On Wolff's $L^{\frac{5}{2}}-$Kakeya maximal inequality in $\R^3$

Abstract: We reprove Wolff's $L<sup>{\frac{5}2}-$ bound for the $\R<sup>3-$Kakeya maximal function without appealing to the argument of induction on scales. The main ingredient in our proof is an adaptation of Sogge's strategy used in the work on Nikodym-type sets in curved spaces. Although the equivalence between these two type maximal functions is well known, our proof may shed light on some new geometric observations which is interesting in its own right.