Stabilization of Tsirelson-type norms on ell_p spaces

We consider classical Tsirelson-type norms of $T[A_r,\theta]$ and their modified versions on $\ell_p$ spaces. We show that for any $1<p<\infty$ there is a constant $\lambda_p$ such that considered Tsirelson-type norms do not $\lambda_p$-distort any of subspaces of $\ell_p$.