Carles Sáez
@csaezmath.bsky.social
I used to do math professionally, now I learn math as a hobby. Statistician at work, geometer at heart.
Reposted by Carles Sáez
🐴 Que un caballo te mande al otro barrio de una patada, además de poco aconsejable, es muy extraño.
Pero esa extrañeza contribuyó a que se popularizase el que hoy es uno de los modelos de probabilidad más usados del mundo.
Con ustedes: Bortkiewicz, coces de caballos y la distribución de Poisson.
Pero esa extrañeza contribuyó a que se popularizase el que hoy es uno de los modelos de probabilidad más usados del mundo.
Con ustedes: Bortkiewicz, coces de caballos y la distribución de Poisson.
October 25, 2025 at 10:59 AM
🐴 Que un caballo te mande al otro barrio de una patada, además de poco aconsejable, es muy extraño.
Pero esa extrañeza contribuyó a que se popularizase el que hoy es uno de los modelos de probabilidad más usados del mundo.
Con ustedes: Bortkiewicz, coces de caballos y la distribución de Poisson.
Pero esa extrañeza contribuyó a que se popularizase el que hoy es uno de los modelos de probabilidad más usados del mundo.
Con ustedes: Bortkiewicz, coces de caballos y la distribución de Poisson.
Reposted by Carles Sáez
I'll order these so that I can tick them off a list on my computer; the numbers are not any sort of ranking. Summaries will be kept brief and hopefully stoke curiosity, rather than providing answers.
Have been rather quiet on here recently (for uninteresting and unconcerning reasons), but this shouldn't be taken as a lack of enthusiasm for papers which have been coming out recently - loads of really clever and creative works popping up. Will try to post about some of them this afternoon!
October 4, 2025 at 2:53 PM
I'll order these so that I can tick them off a list on my computer; the numbers are not any sort of ranking. Summaries will be kept brief and hopefully stoke curiosity, rather than providing answers.
Reposted by Carles Sáez
The first talk of the season will be this coming Tuesday (23 September), given by Alexandre Bouchard-Côté from UBC. Alex is a great speaker, so do join if you have the chance!
See sites.google.com/view/monte-c... for details, links, and so on.
See sites.google.com/view/monte-c... for details, links, and so on.
September 19, 2025 at 3:23 PM
The first talk of the season will be this coming Tuesday (23 September), given by Alexandre Bouchard-Côté from UBC. Alex is a great speaker, so do join if you have the chance!
See sites.google.com/view/monte-c... for details, links, and so on.
See sites.google.com/view/monte-c... for details, links, and so on.
Reposted by Carles Sáez
A crazy open problem in algebra:
Conjecture (Poonen): 100% (asymptotic density) of finite commutative rings have characteristic EXACTLY 8, i.e. 4 ≠ 0 and 8 = 0 both hold.
From this amazing paper: arxiv.org/abs/math/060...
Conjecture (Poonen): 100% (asymptotic density) of finite commutative rings have characteristic EXACTLY 8, i.e. 4 ≠ 0 and 8 = 0 both hold.
From this amazing paper: arxiv.org/abs/math/060...
The moduli space of commutative algebras of finite rank
The moduli space of rank-n commutative algebras equipped with an ordered basis is an affine scheme B_n of finite type over Z, with geometrically connected fibers. It is smooth if and only if n <= 3. I...
arxiv.org
August 17, 2025 at 2:41 PM
A crazy open problem in algebra:
Conjecture (Poonen): 100% (asymptotic density) of finite commutative rings have characteristic EXACTLY 8, i.e. 4 ≠ 0 and 8 = 0 both hold.
From this amazing paper: arxiv.org/abs/math/060...
Conjecture (Poonen): 100% (asymptotic density) of finite commutative rings have characteristic EXACTLY 8, i.e. 4 ≠ 0 and 8 = 0 both hold.
From this amazing paper: arxiv.org/abs/math/060...
Reposted by Carles Sáez
im devastated to learn that i write with a lisp (it's not as bad as some other but still (it makes me feel a little self-conscious (not that there's anything wrong with lisps (i think it's cute, actually (sometimes)))))
August 13, 2025 at 3:55 PM
im devastated to learn that i write with a lisp (it's not as bad as some other but still (it makes me feel a little self-conscious (not that there's anything wrong with lisps (i think it's cute, actually (sometimes)))))
Reposted by Carles Sáez
Me in 2023: Just chill. All the AI doom scenarios involve giving models direct access to and control over real world systems, and no one would be that dumb
In 2025: oh fuck
In 2025: oh fuck
August 9, 2025 at 2:12 PM
Me in 2023: Just chill. All the AI doom scenarios involve giving models direct access to and control over real world systems, and no one would be that dumb
In 2025: oh fuck
In 2025: oh fuck
Reposted by Carles Sáez
GPT-5 regularly asks you why you are not citing its work. GPT-5 always believes your estimator is biased. GPT-5 has more of a comment than a question. Sometimes GPT-5 tells you stories about grad school and expresses regret about getting a PhD. GPT-5's mom wonders when it will start making money.
“GPT-5 is the first time that it feels like talking to an expert in any topic — a Ph.D.-level expert,” OpenAI CEO Sam Altman said.
OpenAI Unveils GPT-5, Its Latest and Most Powerful Model, After Two-Year Wait
CEO Sam Altman said using the chatbot will be like talking with a doctorate-level expert in any topic.
www.wsj.com
August 7, 2025 at 8:22 PM
GPT-5 regularly asks you why you are not citing its work. GPT-5 always believes your estimator is biased. GPT-5 has more of a comment than a question. Sometimes GPT-5 tells you stories about grad school and expresses regret about getting a PhD. GPT-5's mom wonders when it will start making money.
Reposted by Carles Sáez
Reposted by Carles Sáez
Prepping my post-BayesComp "stock market update" (to be taken with a pinch of salt!) on how different topics fared relative to my expectations / past years.
July 26, 2025 at 3:49 PM
Prepping my post-BayesComp "stock market update" (to be taken with a pinch of salt!) on how different topics fared relative to my expectations / past years.
Reposted by Carles Sáez
Deltarune............................................................ tomorrow!
June 3, 2025 at 12:43 PM
Deltarune............................................................ tomorrow!
Reposted by Carles Sáez
Per a quins valors n²+5n+6 és quadrat perfecte?
Resolem aquest problema d'olimpíada amb àlgebra, anàlisi, teoria de nombres... i inclús estadística!
sites.google.com/view/rubenmu...
Resolem aquest problema d'olimpíada amb àlgebra, anàlisi, teoria de nombres... i inclús estadística!
sites.google.com/view/rubenmu...
Rubén Musoles Roca - Problema 1 - OCM 2022
En aquesta entrada donaré diverses solucions del primer problema de l'Olimpíada Matemàtica (OMC) del curs 22-23 (fase Catalana). El que més m'agrada és la diversitat de resolucions que he anat recolli...
sites.google.com
May 27, 2025 at 6:51 PM
Per a quins valors n²+5n+6 és quadrat perfecte?
Resolem aquest problema d'olimpíada amb àlgebra, anàlisi, teoria de nombres... i inclús estadística!
sites.google.com/view/rubenmu...
Resolem aquest problema d'olimpíada amb àlgebra, anàlisi, teoria de nombres... i inclús estadística!
sites.google.com/view/rubenmu...
Reposted by Carles Sáez
Pretty funky: for state-space models, one usually teaches things in terms of a Markovian latent state {x_t}, with conditionally-independent emissions y_t which depend only on x_t.
Actually, a good chunk of the tractability of SSMs is preserved when the emissions depend on both of (x_{t - 1}, x_t)!
Actually, a good chunk of the tractability of SSMs is preserved when the emissions depend on both of (x_{t - 1}, x_t)!
April 27, 2025 at 12:52 PM
Pretty funky: for state-space models, one usually teaches things in terms of a Markovian latent state {x_t}, with conditionally-independent emissions y_t which depend only on x_t.
Actually, a good chunk of the tractability of SSMs is preserved when the emissions depend on both of (x_{t - 1}, x_t)!
Actually, a good chunk of the tractability of SSMs is preserved when the emissions depend on both of (x_{t - 1}, x_t)!
Reposted by Carles Sáez
Reposted by Carles Sáez
April 14, 2025 at 11:33 PM
Reposted by Carles Sáez
one time i tried to introduce myself to an ♾️-cat guy and before i could say anythind he told me "follows from a construction of deligne." i said "sorry? I--" he said "corollary of Stacks Project 4.13.2." I said "I'm Rochelle" and he said "I know; its in Lurie."
sorry liberals but all of mathematics is a special case of a construction in enriched (∞, ∞)-category theory
April 15, 2025 at 3:09 AM
one time i tried to introduce myself to an ♾️-cat guy and before i could say anythind he told me "follows from a construction of deligne." i said "sorry? I--" he said "corollary of Stacks Project 4.13.2." I said "I'm Rochelle" and he said "I know; its in Lurie."
Reposted by Carles Sáez
Reposted by Carles Sáez
Fíjate bien, que no es el Mundo Today.
El vicepresidente JD Vance en Groenlandia: “Aquí hace un frío que te cagas”
EEUU redobla la presión sore Groenlandia con la visita de una delegación estadounidense en la isla ártica
www.eldiario.es
March 28, 2025 at 6:47 PM
Fíjate bien, que no es el Mundo Today.
Reposted by Carles Sáez
Reposted by Carles Sáez
The most dangerous thing about AI chat bots is how many men with political power treat them *exactly* and unquestioningly like actual Ancient Greek oracles.
March 22, 2025 at 12:19 AM
The most dangerous thing about AI chat bots is how many men with political power treat them *exactly* and unquestioningly like actual Ancient Greek oracles.
Reposted by Carles Sáez
I used to think the phrase "free gift" was redundant but now I realize they are just gifts that are characterized by the usual universal property.
March 19, 2025 at 11:37 PM
I used to think the phrase "free gift" was redundant but now I realize they are just gifts that are characterized by the usual universal property.
Reposted by Carles Sáez
Alternately laughing, crying, and throwing up contemplating this area computation.
I… did not expect a rational number with 108 digits in its reduced denominator to occur as the answer to the fairly natural question “what is the area of the Pythagoras tree fractal?”. penteract.github.io/pythagTree.h... 😲
March 18, 2025 at 7:26 PM
Alternately laughing, crying, and throwing up contemplating this area computation.
Me 90% of the days (and most of the time the email isn't even difficult 🥲)
damn, I was hoping to do other things today than replying to one difficult email
March 17, 2025 at 2:04 PM
Me 90% of the days (and most of the time the email isn't even difficult 🥲)
Reposted by Carles Sáez
oh cool news in the red there!
March 9, 2025 at 7:37 PM
oh cool news in the red there!
TIL Lie algebra are nazi
With the recent ascendancy of fascism, it seems like things with even superficial similarity to facist signifiers will absorb those meanings. 🫤
Here’s where I learned about fraktur being the nazi font. It gives the background (but is not nazi propaganda).
99percentinvisible.org/episode/frak...
Here’s where I learned about fraktur being the nazi font. It gives the background (but is not nazi propaganda).
99percentinvisible.org/episode/frak...
Fraktur - 99% Invisible
Peter Dörfell lives in Dresden Germany where he works in elder care, visiting clients at their homes, and to do that, he usually takes the bus. But one morning last September, he noticed something unu...
99percentinvisible.org
March 8, 2025 at 8:23 AM
TIL Lie algebra are nazi