Monthly Archives: April 2020

Picard Groups of Moduli Stacks

Posted on April 30, 2020 by Persiflage

Here are some algebraic geometry musings related to the last post, most of which is hopefully correct. Everything below is secretly over \(\mathbf{Z}[1/6]\) but I think one may as well think about what is happening over \(\mathbf{C}\). Warning: I don’t … Continue reading →

Posted in Mathematics | Tagged , , , , , , , , , , | 9 Comments

Chidambaram on genus two curves, II

Posted on April 24, 2020 by Persiflage

We now continue a series of posts on the work of my student Shiva Chidambaram. (Click here for part I.) Today I would like to discuss another project with Shiva that was also joint with David Roberts (no, not David … Continue reading →

Posted in Mathematics, Students, Work of my students | Tagged , , , , , , , , , | 2 Comments

En Passant VIII

Posted on April 23, 2020 by Persiflage

I just found out that Lucien Szpiro recently passed away. I met him only once in late 2018 when I gave the joint NY number theory at CUNY. When I arrived at my hotel (the Gregory) around 10pm, I was … Continue reading →

Posted in Mathematics | Tagged , , , , | Leave a comment

En Passant VII

Posted on April 19, 2020 by Persiflage

Idle question which has surely been asked (and answered!). If \(X^{+}_{\mathrm{nsp}}(p)\) is the modular curve corresponding to the normalizer of the non-split Cartan, then one reason it is hard to find all rational points is that the all factors of … Continue reading →

Posted in Mathematics | Tagged , , | 4 Comments

Chidambaram on genus two curves, I

Posted on April 15, 2020 by Persiflage

Before we start, just to alert you to a minor blogpage design change: all the posts (including this one) which talk about my students work can be accessed in one place by clicking the “work of my students” tab just … Continue reading →

Posted in Mathematics, Students | Tagged , , , , , , , , , , , , | 8 Comments