The matrix $A_2$ conjecture fails, i.e. $3/2>1$

Komla Domelevo, Stefanie Petermichl, Sergei Treil +1

We show that the famous matrix $A_2$ conjecture is false: the norm of the Hilbert Transform in the space $L^2(W)$ with matrix weight $W$ is estimated below by $C[W{]}_{A_2}^{3/2}$.