Fernando Rodriguez Villegas
Recent Writing
Water and IceFebruary 13, 2025
Water and ice En un sueño lejano,
como un recuerdo en la niebla,
aparece Borges.
Escritor de Buenos Aires, ciego.
Escritor no del amor sino del espanto.
Aparece como el capitán de un equipo de rugby
arengando a sus compañeros en el vestuario:
“Muchachos, a ver si nos entendemos,
el hielo existe”
Transición de fase lo llaman los físicos,
como la muerte.
Un día sos, al otro día no.
El agua fluye, el hielo se queda donde está.
read moreBellunoFebruary 4, 2025
En Belluno para el bendito PET. Casi cuatro horas de tren desde Trieste. Lindo paisaje de montaña, nieve en las cimas a lo lejos.
Belluno bonita en el sol brillante y el aire límpido. Claramente del Veneto, extraño Venezia en las montañas. Piazza dei Martiri antes fuera delle mura de la ciudad. Un cono de nieve sucia a la sombra de unos árboles en la plaza. Piazza arcuata, edificios en curva a 92 m de la muralla, dos metros mas que el alcance de los arcabuses de la época.
read moreHow to eat a maritozzoJanuary 26, 2025
The first thing to understand is that the question of the title is not a trivial one, especially if you have a beard.
So what is a maritozzo? It’s a Roman pastry consisting of a ball of sweet bread with a big gash in the middle completely filled with whipped cream. The New York Times calls them unnapealingly “Sweet Cream Buns”, which doesn’t even begin to do them justice. It seems that maritozzi have become quite a thing in the US from what I can gather online.
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Two nights at Cattinara (in Spanish)
On Randomness
Hamilton and the Discovery of Quaternions
A Large Language Model in the 1700s?
All WritingRecent Math
Special parametersOctober 8, 2024
An old paper (Über hypergeometrische Funktionen, deren letztes Element speziell ist) by W. Heymann (from a talk by Wadim Zudilin) discusses the value of an ${}_2F_1$ at special $t$’s. He does $t=-1/3,1/4,1/5$ and related values and mentions Gauss for $t=1,-1,1/2$ and Kummer for $t=-1/8,1/9,8/9$.
For example we have this identity $$ F_h = F \left( -\frac{h}{2}, -\frac{h}{2} + \frac{1}{2}, h + \frac{3}{2}, -\frac{1}{3} \right) = \frac{2}{3} \cdot \left( \frac{8}{9} \right)^h \cdot \frac{\Gamma \left( \frac{1}{3} \right) \cdot \Gamma \left( h + \frac{3}{2} \right)}{\sqrt{\pi} \cdot \Gamma \left( h + \frac{4}{3} \right)} $$ If we take $h=1/2$ we get an HGM defined over $\mathbb Q$, we get the gamma vector $[-4,1,1,2]$ and corresponding Weierstrass model $$ y^2+xy=x^3+\frac t{64}x.
read moreExperimental Number TheoryAugust 31, 2024
This book, published in 2007, is a discussion of various mathematical experiments in Number Theory using the computer. The main computational tool used is the sophisticated package PARI-GP. Maybe the best way to describe the book in more detail is to just quote its preface.
Preface -------- There is a long and distinguished tradition in mathematics, perhaps even more pronounced in number theory, whereas a chance discovery of a pattern or identity between numbers arising from unrelated calculations leads to the development of whole new fields (this is precisely how Gauss phrases it in a diary entry).
read moreHGMJuly 19, 2024
This project got started at a fabulous workshop held in Benasque, Spain (in the mountains, a few hours drive from Barcelona) in 2009. I wrote this post in my blog after returning from another workshop there on p-adic analysis in 2007. In my own notes I added:
The place is truly amazing. Mountains falling over you as you walk down the street.
The plan of the 2009 workshop was to explore ways to compute exotic L-functions, not arising from elliptic curves or usual modular forms.
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The Mathematics of the Football
Counting quiver representations over finite fields
Mixed Hodge Numbers and Factorial Ratios
Blet
All MathRecent Cooking
Scoplit pestoMarch 10, 2025
One of the joys of cooking (of living!) in Italy is the variety of products you can find in the market.
Supermarkets tend to be small (navigating them at peak time a challenge) and the selection limited but the quality is always very high. You could basically buy anything with your eyes closed and not be dissapointed (or ruin your appetite or your health if repeated).
I am thinking specifically of the farmer’s markets in the public squares and the incredible variety of vegetables and especially herbs you might find.
read moreMushrooms with blue cheeseNovember 15, 2024
I am not sure where I got this from. I do remember my aunt, the writer Alicia Plante, back in Buenos Aires, mentioning a recipe of baked fish with blue cheese that I prepared a few times. In the US I adapted it using big mushrooms instead of fish. But maybe I got the idea somewhere else.
1 Get some big round mushrooms, for example, shitake mushrooms. I read that one should never wash the mushrooms with water as they get ruined somehow but gently remove any impurities with a soft brush.
read morePasta verdeNovember 2, 2024
After a fair number of iterations this is the result of my cooking pasta with greens. At home we just call it Pasta Verde. This version is with Swiss chard but a real nice combination is dandelion leaves (tarassaco in Italian) and Swiss chard (bieta). You can see how the various steps follow those for cooking a risotto.
1 Start preparing about an hour in advance a thick broth to use to cook the pasta.
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