Postnikov, Alexander

Alexander Postnikov
MIT School of Mathematics
Cambridge, Massachusetts

ArXiv: Scattering Amplitudes and the Positive Grassmannian (2012), Cosmological Polytopes and the Wavefunction of the Universe (2017), Positive Grassmannian and polyhedral subdivisions (2018)
Homepages: MIT-Mathematics (MIT-ILP)

 First email: December 17, 2020 @ 1:31 PM

Dear Prof. Dr. Alexander Postnikov,

Long, long ago in the office of Gian-Carlo Rota, I had asked enough stupid questions (BU at that time), he suggested that I should come study with them. It was like an invitation from god to come to the Vatican to study with the pope.

I smiled politely and got out of there before they discovered how little I knew. Today, I am so old, it doesn’t really matter anymore.

Not too long ago, I asked Hamid-Arkani about his positive Grassmannian. He’s a bit anxious, and doesn’t like to be slowed down by nonsense, so he hasn’t had much to say to us.

Our nonsense opens the infinitesimal domain. In fact, our simple, little model, emerging from a New Orleans high school class has at least 64 base-2 notations before we get into the quark-gluon plasma. We started at the Planck base units and assumed a very cold start. Everything, everywhere, for all time was encapsulated within 202 notations. It’s efficient, but is it meaningful? is where I explore things in my plebeian way. In your Positive Grassmannian paper, page 3, you thank all the people who helped you with insights. There are only a handful of names that I recognized and it is good to know there is such a group working on these concepts. Although I obviously work at a simple level of generality and might easily fly over “8.3.Triangulations and zonotopal tilings,” I am constantly thinking of my friends working within string theory and others with Langlands programs. Those 64 notations open many possible ways to begin speculatively assigning your work to specific notations just to see if there could be hooks to these other rigorous studies.

Perhaps, our work is only good for a laugh, but perhaps it is good because it opens a bit of space for other explorations. Nonsense? Thank you.