Author Archives: Persiflage

The congruence subgroup property for thin groups.

I finally had a chance to visit Yale, which (by various orderings) is the fanciest US university at which I had never given a talk (nor even visited). The town itself struck me, at first, as a cross between Oxford … Continue reading

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Short thoughts on my visit to Berkeley

The marine biologists at Monterey Bay Aquarium give their octopuses hand massages. So do the fishmongers at Eataly. It’s quite an experience to come face to face with this antediluvian monster:  Are you allowed to turn right on red in … Continue reading

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Local crystalline deformation rings

I just returned from a very pleasant conference in Puerto Rico courtesy of the Simons Foundation (general advice: if you live in Chicago, always accept invitations to conferences in January). One thing I learnt from Toby Gee was the following … Continue reading

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Gross Fugue

Here are some variations on the theme of the last post, which is also related to a problem of Dick Gross. In this post, I want to discuss weight one modular forms where the level varies in the “vertical” aspect … Continue reading

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The mystery of the primes

No, this is not the sequel to Marcus du Sautoy’s book, but rather a curious observation regarding George Schaeffer’s tables of “ethereal” weight one Katz modular eigenforms (which you can find starting on p.64 here). Let \(N\) be a positive … Continue reading

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Daleks

I’ve wanted to write a post about the new Doctor Who series for a while, but this is not that post. Instead, this post is about a Macintosh game called Daleks, which I first played on a Mac 512 (running … Continue reading

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What is my Kasparov Number?

This has been a fun week in sport, what with England slaughtered at the Gabbatoir and Anand sliced up by Carlsen’s endgame magic. The latter games were fascinating if not necessarily exciting per se; consisting more of slow grinds rather … Continue reading

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Local representations occurring in cohomology

Michael Harris was in town for a few days, and we chatted about the relationship between my conjectures on completed cohomology groups with Emerton and the recent work of Scholze. The brief summary is that Scholze’s results are not naively … Continue reading

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Abelian Varieties

Jerry Wang gave a nice talk this week on his generalization of Manjul’s work on pointless hyperelliptic curves to hyperelliptic curves with no points over any field of odd degree (equivalently, \(\mathrm{Pic}^1\) is pointless). This work (link here) is joint … Continue reading

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The problem with baseball

Jordan Ellenberg, in a lovely slate article, explains perfectly what I don’t like about baseball. I think the fundamentals of baseball as a sport are sound. I like the pace of the game, the variation, the statistics, the quirkiness, the … Continue reading

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