Category Archives: Mathematics

The seven types of graduate student applicant

Posted on March 29, 2015 by Persiflage

Yes, it’s that time of year again. Hide and Seek: Contacts you every day about the status of their application, then goes on radio silence the moment they receive an offer, never to be heard of again. The No Chancer: … Continue reading →

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Review of Buzzard-Gee

Posted on March 3, 2015 by Persiflage

This is a review of the paper “Slopes of Modular Forms” submitted for publication in a Simons symposium proceedings volume. tl;dr: This paper is a nice survey article on questions concerning the slopes of modular forms. Buzzard has given a … Continue reading →

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H_2(Gamma_N(p),Z)

Posted on January 30, 2015 by Persiflage

In this post (which is a follow-up to the last post), I wanted to compute the group \( H_2(\Gamma_N(p),\mathbf{Z})\), where \( \Gamma_N(p)\) is the congruence subgroup of \( \mathrm{SL}_N(\mathbf{Z})\) for large enough \( N\) and \( p\) is prime. In … Continue reading →

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Stable completed homology without Quillen-Lichtenbaum

Posted on January 21, 2015 by Persiflage

Having just made (hopefully) the final revisions on my paper on stable completed cohomology groups, I wanted to record here a few remarks which didn’t otherwise make it into the paper. The first is that, in addition to the result … Continue reading →

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Inverse Galois Problems II

Posted on January 13, 2015 by Persiflage

David Zywina was in town today to talk about a follow up to his previous results mentioned previously on this blog. This time, he talked about his construction of Galois groups which were simple of orthogonal type, in particular, the … Continue reading →

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Abelian Spiders

Posted on January 11, 2015 by Persiflage

This is a blog post about the thesis of my student Zoey Guo, who is graduating this year. (For a blog post on the thesis of my other student graduating this year, see this.) Let \(\Phi\) be a finite graph. … Continue reading →

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Higher direct images of canonical extensions

Posted on January 4, 2015 by Persiflage

I like Kai-Wen’s talks; he gives lots of examples, writes big with big chalk, and clearly explains the key points of the argument. I’m not sure I would classify his thesis as light reading material, but if he produced a … Continue reading →

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Derived Langlands

Posted on December 22, 2014 by Persiflage

Although it has been in the air for some time, it seems as though ideas from derived algebraic geometry have begun to inform developments in the Langlands program. (A necessary qualifier: I am talking about reciprocity in the classical arithmetic … Continue reading →

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Harris 60

Posted on December 15, 2014 by Persiflage

I’ve just returned from the excellent MSRI workshop which honored Michael Harris’ 60th birthday, and here is a brief summary of some of the gossip and mathematics I picked up when I was there. First, let me take note of … Continue reading →

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The Modular Forms Database is Annoying

Posted on November 23, 2014 by Persiflage

It used to be the case, 10 or so years ago, that William Stein maintained a website with extensive tables of \(q\)-expansions of modular forms, computed using magma. However, as the edifice of civilization begins to crumble, this website no … Continue reading →

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