Thanks for the post, Sean! You always manage to convey ideas so much more eloquently than me, even the topic of my own thesis. My friends who ask about my research are all getting directed here. Speaking of friends . . .

It’s really good to hear from some old friends out there. My years in grad school wouldn’t have been nearly as cool without you — thanks. Best of luck to you too!

,
Jennie

We met a couple of years ago in Santa Barbara and I’m sure Nick Jones and Amanda Weltman (if they are reading this) will recall Jennie’s little epic with her camera during a climbing trip we all took…

Jeff

Nice to hear from you! Unfortunately I have moved on and is not in Chicago to attend Jennie’s defense and party. But fear not! I will be wiping tears of joy here at Yale!

Heureka! Where is the monkey?

Celebrate! Have a monumental party. I am truly happy for you,
Your friend,
Bjorn

“Maxwell’s equations and their p-form generalization make sense when spacetime is any Lorentzian manifold. However, to get a theory where initial data determine a unique global solution, we want our spacetime to be “globally hyperbolic”, which means that it has a “Cauchy surface”: roughly, a spacelike surface that any sufficiently long timelike curve hits precisely once. To get a good quantum theory of p-form electromagnetism with a Hilbert space of states on which time evolution acts as unitary operators, we need more: our spacetime should be ‘stationary’, meaning that it has time translation symmetry. Otherwise there’s no way to define energy and the vacuum state – which is defined to be the least-energy state.”

Does the preceding paragraph argue for alpha invariant over time by reason of a fundamental mathematical requirement?

Best of luck.

Congratulations! Hope the job hunt goes well!