The tree property on long intervals
An old project in set theory is to force the tree property at every regular cardinal above $\omega_1$. We present the current state of the art towards it, by obtaining the tree property at every regular in the interval $\left[\omega_2, \aleph_{\omega^2+3}\right]$. This is the first construction where the tree property holds across a singular strong limit. This is joint work with Cummings, Hayut, Magidor, Neeman, and Unger.