Hello everyone, This is a follow-up to the CQI seminar email earlier today for the mini-talk "Musings on the space of Hamiltonians". Since this informal talk was announced (and planned) at the last minute, several people couldn't come, so we've rescheduled it to next Wednesday, 26 April, at 14:30 in D5.01. I've included a short title and abstract below. As always you can join us online at https://meet.jit.si/cqi-demon-M6QW9V7YY. Warmly, Will Speaker: Will Schober (that's me) Title: "Musings on the space of Hamiltonians" or, "Global phases are a monkey wrench in the works" Abstract: Most eligible Hamiltonians are not needed to completely describe quantum dynamics; a bounded subset of the Hermitian matrices is sufficient to generate the unitary group. I advocate removing the rest. The identification of global phases for state vectors induces a further reduction of the necessary Hamiltonians. Some strange geometry arises as a result.