Alexander Grothendieck was a titan in his field, making deep connections that fuelled a revolution in mathematics, before giving it all up and disappearing. Jacob Aron explores what his work meant ...

Black holes are so strange that physicists have long wondered if they are quite what they seem. Now we are set to find out if they are instead gravastars, fuzzballs or something else entirely ...

Abstract: We consider a linear discrete time-varying input-output system. Our goal is to study the problem of local assignability of the Lyapunov spectrum by static output feedback control. To this ...