Abbas K. Rizi

Science is supposed to know no borders, until every major conference in my field picks the most hostile country to travel to as its venue 💆🏼

#Epidemics10 #NetSci2026 #CCS2026 #IC2S2 🇺🇸

“I have always tried to live in an ivory tower; but a tide of shit is beating at its walls, threatening to undermine it.”

Doing science in contemporary academia, with its endless pressure to please grant committees, often feels like this Flaubert’s complaint in an 1872 letter to Turgenev.

What you expect the least from the reviewers and the editor is exactly checking for the main claims!

Being in #academia as someone not from the global north be like:

#phdchat #phdlife

Hmm, this isn’t a cumulative curve, so the interpretation should consider the entire trajectory, not only the late stages of the pandemic. I also wonder whether trust in Sweden stayed constant throughout.

“Physicists are very good and famous for getting the right answers for the wrong reasons.” Why? Here’s a clue: noisy philosophizing!

Sean commenting on Nima's talk, Two Cheers for Shut Up and Calculate, at the Natural Philosophy Symposium 2025

@pholme.bsky.social's feed

We are hiring multiple PhD and postdocs for two newly funded projects at the intersection of mental health and political polarization at the CS Dept at Aalto, Finland. The PIs are Juhi Kulshrestha, Talayeh Aledavood, and Mikko Kivelä.

Full call text and link to apply: www.aalto.fi/en/open-posi...

We should switch from paper to screen posters—more eco-friendly and far more engaging. Elisa’s poster already showed us how creative this can be.

@elisamurators.bsky.social @cssociety.bsky.social

Thank you for this opportunity. The slides of my talk & the preprint are available at abbas.sitpor.org

Excited to present 2 of our recent works at @css-conference.bsky.social

“Social & Special Landscape of Covid-19 Immunity in Denmark”
- Tue at 15:30, Room 13
- Thu at 12:30, Old Chapel Room

“Homophily Within and Across Groups”
- Thu at 10:30, Room 13, CSS Satellite

PNAS: Strength and weakness of disease-induced herd immunity in networks
https://www.pnas.org/doi/abs/10.1073/pnas.2421460122?af=R

@jsaramak.bsky.social you will love this!
Permanent link to this comic: xkcd.com/833/

I also love Lobachevsky. So sad to hear that Lehrer is gone!

IC2S2'25 Norrköping - YouTube This playlist contains all keynotes from IC2S2'25 in Norrköping, Sweden.

All the keynote recordings are available now, enjoy! www.youtube.com/playlist?lis...

Yaaay! Tnx 😄

Cool logo, BRAN Lab!

Has this talk been recorded, by any chance?

Sam works at the intersection of artificial intelligence and public health, leveraging AI to enhance our understanding and management of infectious diseases. He is Prof. of Machine Learning & Public Health at the Uni. Copenhagen and Prof. of Statistics & Public Health at Imperial College London.

YouTube video by Abbas K. Rizi AI & Public Health: Between Hype and Hope — with Samir Bahtt

AI & Public Health: Between Hype and Hope — Interview with Samir Bahtt
youtu.be/L-_pFPOZvV0

From outbreak forecasting to shaping public policy, AI promises transformative impacts—but what are its true capabilities and limitations?
@sjbhatt.bsky.social

Strength and weakness of disease-induced herd immunity in networks | PNAS When a fraction of a population becomes immune to an infectious disease, the population-wide infection risk decreases nonlinearly due to collective...

New paper in PNAS!🎉 doi.org/10.1073/pnas...

Is herd immunity to infectious diseases effective when induced by natural infection? Earlier studies have suggested that population heterogeneity makes disease-induced herd immunity more effective than previously thought. Our work challenges this notion.

Strength and weakness of disease-induced herd immunity in networks | PNAS When a fraction of a population becomes immune to an infectious disease, the population-wide infection risk decreases nonlinearly due to collective...

Read the paper here for free: pnas.org/doi/10.1073/pnas.2421460122

And here is a less technical blog post for a more general reader:
abbas.sitpor.org/2025/07/10/t...

Kudos to @takayukihir.bsky.social, @bolozna.bsky.social, @jsaramak.bsky.social, and our one-and-only Zahra Ghadiri.

2/2

What if #herd_immunity isn’t just about how many people are immune, but how they’re 'spatially' connected? Our new PNAS paper explores this concept. We show how the topology and geometry of social networks influence the dynamics of herd immunity, whether it arises from infection or #vaccination. 1/2

Lost in Retraining: Roaming the Parameter Space of Exponential Families Under Closed-Loop Learning Closed-loop learning is the process of repeatedly estimating a model from data generated from the model itself. It is receiving great attention due to the possibility that large neural network models ...

1/3 What happens if one repeatedly retrains a machine on data primarily generated from itself? For example when students use LLMs to write their essays that they then put online. And then profs use LLMs to write a paper on that topic and so on 😎
arxiv.org/abs/2506.20623

What is #emergence, after all?
arxiv.org/abs/2507.04951

We unpack its meaning across science & philosophy, drawing on examples ranging from physics to bird flocking & epidemics. We feature how #herd_immunity emerges as immune individuals form overlapping firewalls that grow into a dominant shield.

Indeed, the US has more than an instinct to care beyond its borders!

My "Math, Revealed" series is freely available to anyone -- no paywall! -- in the thread below.

Are you interested in doing a PhD in data science in Denmark?

The Danish Advanced Research Academy (DARA) has open PHD calls 👇

Reach out to me if you are interested in
1) ML/AI robustness
2) Algorithmic fairness
3) Intersection of Climate change and human behavior

daracademy.dk/fellowship/f...

Presented our work with @c0rrad0.bsky.social, @bolozna.bsky.social, and Barbara Keller on user behavior change after cross-party interactions at #ICWSM today! Was a great experience and got a lot of interesting questions 🙌
Also: currently looking for postdoc opportunities - happy to chat!

@sunelehmann.com got me thinking:

Are there things that will always remain beyond human understanding, but not for AI? Is there a cognitive upper bound for us—due to our biology—much like a cat can't grasp the mathematics of spacetime curvature?

Oh, and the reference totally sealed the deal 😄