Borel equivalence relations between \ell_1 and \ell_p
  In this paper, we show that, for each $p>1$, there are continuum many Borel equivalence relations between $\Bbb R^\omega/\ell_1$ and $\Bbb R^\omega/\ell_p$ ordered by $\le_B$ which are pairwise Borel incomparable. 
Longyun Ding and Zhi Yin
math.LO math.FA