Zusammenfassung
We survey the techniques used in our recent resolution of the Kadison–Singer problem and
proof of existence of Ramanujan Graphs of every degree: mixed characteristic polynomials and the
method of interlacing families of polynomials. To demonstrate the method of interlacing families of
polynomials, we give a simple proof of Bourgain and Tzafriri’s restricted invertibility principle in the isotropic case.
Nutzer