Author Archives: Persiflage

En Passant IV

My students Richard Moy and Joel Specter have uploaded their paper on partial weight one Hilbert modular forms, previously discussed here, to the ArXiv. Germany now leads the world in both soccer and perfectoid spaces. This is a recipe for … Continue reading

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

A public service announcement concerning Fontaine-Mazur for GL(1)

There’s a rumour going around that results from transcendence theory are required to prove the Fontaine-Mazur conjecture for \(\mathrm{GL}(1)\). This is not correct. In Serre’s book on \(\ell\)-adic representations, he defines a \(p\)-adic representation \(V\) of a global Galois group … Continue reading

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

Report from Luminy

For how long has Luminy been infested with bloodthirsty mosquitoes? The combination of mosquitoes in my room with the fact that my bed was 6′ long with a completely unnecessary headboard (which meant that I had to sleep on an … Continue reading

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

An Obvious Claim

It’s been a while since I saw Serre’s “how to write mathematics badly” lecture, but I’m pretty sure there would have been something about the dangers of using the word “obvious.” After all, if something really is obvious, then it … Continue reading

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

Huuuuuge piles of cash

As widely reported today, the first of the “Breakthrough” prizes in mathematics have been announced. Leaving aside the question as to whether such awards are sensible (Persiflage is more sympathetic to capitalist principles than your average pinko marxist mathematician), I … Continue reading

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

There are non-liftable weight one forms modulo p for any p

Let \(p\) be any prime. In this post, we show that there is an integer \(N\) prime to \(p\) such that \(H^1(X_1(N),\omega_{\mathbf{Z}})\) has a torsion class of order \(p\). Almost equivalently, there exists a Katz modular form of level \(N\) … Continue reading

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

Math and Genius

Jordan Ellenberg makes a compelling case, as usual, on the pernicious cultural notion of “genius.” Jordan’s article also brought to mind a thought provoking piece on genius by Moon Duchin here (full disclosure: the link on Duchin’s website has the … Continue reading

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

I don’t know how to prove Serre’s conjecture.

I find it slightly annoying that I don’t know how to prove Serre’s conjecture for imaginary quadratic fields. In particular, I don’t even see any particularly good strategy for showing that a surjective Galois representation — say finite flat with … Continue reading

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

Thurston, Selberg, and Random Polynomials, Part II.

What is the probability that the largest root of a polynomial is real? Naturally enough, this depends on how one models a random polynomial. If we take polynomials of degree N which are constrained to have all of their roots … Continue reading

Posted in Mathematics | Tagged , , , , | 1 Comment

Thurston, Selberg, and Random Polynomials, Part I.

Apart from everything else, you could always count on Bill Thurston to ask interesting questions. This is the first of a small number of posts which were motivated in part by figure two from this paper, and this accompanying MO … Continue reading

Posted in Mathematics, Students | Tagged , , , , , , , , | 6 Comments