Author Archives: Persiflage

A random curve over Q

Posted on April 2, 2022 by Persiflage

Let \(X/\mathbf{Q}\) be a smooth projective curve. I would like to be able to say that the motive \(M\) associated to \(X\) “generally” determines \(X\). That is, I would like to say it in a talk without feeling like I’m … Continue reading →

Posted in Mathematics | Tagged , , | 16 Comments

ArXiv x 3

Posted on March 4, 2022 by Persiflage

Three recent arXiv preprints this week caught my interest and seemed worth mentioning here. The first is a paper by Oscar Randal-Williams, which considers (among other things) the cohomology of congruence subgroups of \(\mathrm{SL}_N(\mathbf{Z})\) in the stable range. This is … Continue reading →

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What would a good ICM talk look like?

Posted on February 27, 2022 by Persiflage

Now that the ICM has (unsurprisingly) become a virtual event, it might be worthwhile thinking a little bit about what would constitute a good talk in this new setting. There’s a certain electricity to talks given in person, and I … Continue reading →

Posted in Mathematics, Politics | Tagged , , , , | 3 Comments

Boxes for Boxer

Posted on January 4, 2022 by Persiflage

My brother texted me on Monday saying that there were seven (or so) boxes pilled up (outside!) in front of the mathematics department and all addressed to George Boxer. My first thought was that this was a transatlantic move gone … Continue reading →

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

Simons Annual Meeting

Posted on December 23, 2021 by Persiflage

The last time I traveled for math was when I gave the Coble lectures at UIUC pre-pandemic (at least pre-pandemic as far as the US goes). A few months ago it seemed like one could begin to start traveling again, … Continue reading →

Posted in Mathematics, Travel | 3 Comments

Schur-Siegel-Smyth-Serre-Smith

Posted on November 25, 2021 by Persiflage

If \(\alpha\) is an algebraic number, the normlized trace of \(\alpha\) is defined to be \( \displaystyle{T(\alpha):=\frac{\mathrm{Tr}(\alpha)}{[\mathbf{Q}(\alpha):\mathbf{Q}].}}\) If \(\alpha\) is an algebraic integer that is totally positive, then the normalized trace is at least one. This follows from the AM-GM … Continue reading →

Posted in Mathematics | Tagged , , , , , | 5 Comments

Polymath Proposal: 4-folds of Mumford’s type

Posted on August 24, 2021 by Persiflage

Let \(A/K\) be an abelian variety of dimension \(g\) over a number field. If \(g \not\equiv 0 \bmod 4\) and \(\mathrm{End}(A/\mathbf{C}) = \mathbf{Z}\), then Serre proved that the Galois representations associated to \(A\) have open image in \(\mathrm{GSp}_{2g}(\mathbf{Z}_p)\). The result … Continue reading →

Posted in Mathematics | Tagged , , , , , , , , , , , , | 2 Comments

59,281

Posted on August 19, 2021 by Persiflage

The target audience of this blog (especially the mathematics) is usually professional mathematicians in the Langlands program. I do sometimes, however, have posts suitable for a broader mathematical audience. Very rarely though do I have anything (possibly) interesting to say … Continue reading →

Posted in Mathematics | Tagged , , , , , , , , | 14 Comments

Divisors near sqrt(n)

Posted on June 8, 2021 by Persiflage

Analytic Number Theory Alert! An even more idle question than normal (that’s because it comes from twitter). Alex Kontorovich noted with pleasure the following pictorial representation of the integers from a Veritasium youtube video, where prime numbers are represented by … Continue reading →

Posted in Mathematics | Tagged , , , | 5 Comments

Potential Automorphy for GL(n)

Posted on April 29, 2021 by Persiflage

Fresh on the arXiv, a nice new paper by Lie Qian proving potential automorphy results for ordinary Galois representations \(\rho: G_F \rightarrow \mathrm{GL}_n(\mathbf{Q}_p)\) of regular weight \([0,1,\ldots,n-1]\) for arbitrary CM fields \(F\). The key step in light of the 10-author … Continue reading →

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