I’m grateful to the Novo Nordisk Foundation for supporting this project. The fellowship gives me the opportunity to continue exploring how ideas from mathematical infectious-disease modeling can be connected more closely to the practical needs of public health.

Copenhagen Center for Social Data Science (SODAS)@cphsodas.bsky.social · 2d ago

We're delighted that @abbasrizi.bsky.social received Novo Nordisk's Postdoctoral Fellowship for Oxford. 🥳 He'll be there for 2 years, then at SODAS for 1. He'll work on minimal network models for epidemic control, to find out how much complexity is actually needed to guide public health decisions.

Writing a paper [without chatbots] be like spending 8 hours reading 6 papers to write one sentence citing 2 references, and then deleting it the next morning! Or to quote Miranda; "And you write until the rust comes out of the faucet, and it's clear water, and then you write down the clear water."

Sean Carroll@seanmcarroll.bsky.social · last mo.

Productive writing day! I wrote a long, difficult section; read it; decided it was not very good and actually unnecessary; deleted it. But now I *know* that discussion would be unnecessary and bad, so that’s progress.

This reminded me of Susskind’s 2020 interview, back when things felt less broken. He was already worried that popular science was becoming performance: Scientific American, once “the real stuff” from working scientists, now increasingly unscientific, and dangerous because people still trust it!

Dan Falk@danfalk.bsky.social · last mo.

The news from Scientific American this week has been heartbreaking. While the magazine itself will go on under its new owners, many *extremely talented* writers and editors have been let go. I do worry about the future of #science #journalism… 😔

In addition to a hiring PhD in ~October & hopefully some PhDs and postdocs ~February, if anyone would like to work with me as part of eg a Marie-Curie or something similar, please do get in touch. Topics include depression, classification, measurement, systems, time-series, & theory building.

Back in the good old Twitter days, people would attend conferences and share actual scientific highlights from talks and posters. Even if you couldn't be there, you could still follow along through thoughtful threads from colleagues reflecting on the science. 1/3

The Effect of Mobility Trajectory Sparsity on Epidemic Modeling Outcomes https://arxiv.org/abs/2605.31282 GPS mobility data are increasingly used in epidemic modeling, allowing the construction of co-location networks or population flows. These trajectories typically exhibit high temporal spa...📈🤖

From today, science is dead. Or maybe not! Some reflections on how AI is changing the very practice of research or any other creative endeavour: abbas.sitpor.org/2026/05/28/f...

www.nytimes.com/interactive/...

How the U.S.-Israeli Strikes on Iran Have Damaged Schools and Hospitals

The Times has verified U.S.-Israeli strikes on at least 39 schools and hospitals, a fraction of the devastation so far.

nytimes.com

New preprint on arXiv: “Message passing and cyclicity transition” arxiv.org/abs/2604.01201 I argue that message passing for percolation isn’t looking for the giant component; it’s just counting cycles. Comments and feedback welcome!

Message passing and cyclicity transition

Message passing, also known as belief propagation, is a versatile framework for analyzing models defined on graphs. Its most prototypical application is percolation; yet, the interpretation of the mes...

arxiv.org

Pasteur Institute of Iran, founded in 1920 now destroyed by Israel-US bombing😞 It played a pivotal role in developing vaccines & public health services, for over a century, now gone😞 A few days ago a pharmaceutical plant was bombed, accused of making anesthetic fentanyl #War #PasteurInstituteIran

Freeman Dyson once said scientists fall into two types: birds and frogs. Birds fly high above the landscape, drawn to the horizon, looking for connections that tie distant ideas together. Frogs live close to the ground, digging into one problem at a time. Hilbert was a bird. Besicovitch was a frog.

A heartbreaking message from a brilliant med student in Iran, determined to pursue neuroscience. She graduated only one week before the war started and now is volunteering to care for the injured. What would you tell her? (Part #4, especially). Please share your thoughts and comments. #IranWar

This is me in 2017 after the first workshop on complex systems for high school students at Allameh Helli High School in Tehran. Teenage boys and girls were sitting next to each other, curious and full of questions. I loved that school. Seeing it damaged by US and Israeli bombs is heartbreaking.

What is emergence, after all? New PNAS Nexus paper: academic.oup.com/pnasnexus/ar.... In this paper, I clarify the scientific meaning of emergence as a measurable and physically grounded phenomenon through concrete examples, such as temperature, magnetism, and herd immunity in social networks.

If you have an Iranian colleague or friend, this is likely how they feel theses days:

Healthy Debate@healthydebate.bsky.social · 6mo ago

"When the internet is severed, the diaspora is not just worried; we are psychologically confused and helpless." healthydebate.ca/2026/01/topi...

We're already in the phase that each of us (Iranians) by now know someone killed/injured in our circle of friends/family. And this is despite the continued internet blackout, when millions haven't still managed to hear from their family/friends since Thursday, January 8th. This tells a lot ... 😥😥

How did we decide to call a tree “tree”? A bird “bird”? Not now, but in the early days, when there could have been different ways to name or define something. On Language & Poetry | A short post I wrote over the Christmas holidays; abbas.sitpor.org/2025/12/28/o...

What if birds of a feather flock together, but only at specific group sizes? www.nature.com/articles/s41... This is the focus of our new paper, now published in Nature Communications. We introduce a new network model and show how to model and measure homophily to incorporate group variations.

Homophily within and across groups - Nature Communications

People tend to connect with similar others in different groups, shaping how ideas and diseases spread. The authors introduce a data-validated model that captures homophily across group sizes and show ...

nature.com

“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!

Casper Albers 🟥@handle.invalid · 9mo ago

Doing non-causal inference (and being explicit about it), yet using a causal word as second word in the title. If you pay Nature € 10.690, they will publish this in Nature Ageing. I can tell you what I think of that for free. www.nature.com/articles/s43...

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

“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

Sean Carroll@seanmcarroll.bsky.social · 10mo ago

Next up in the talks from the #NaturalPhilosophy Symposium: Nima Arkani-Hamed offers Two Cheers for Shut Up and Calculate. (He previously was giving three cheers, but he's changed his mind just a bit.) Comments from me, of all people. www.youtube.com/watch?v=72QL...

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

Conference on Complex Systems@css-conference.bsky.social · 11mo ago

Thrilled to announce the Best Poster Awards at CCS2025 go to Simay Atasoy Bingöl, Salvatore Citraro, and Elisa Muratore — congratulations! 🏆✨ #CCS2025

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

Homophily Within and Across Groups

Homophily-the tendency to connect with similar others-plays a central role in shaping network structure and function. It is often treated as a uniform, global parameter, independent from other structu...

arxiv.org

Luca Gallo@lgajo.bsky.social · 11mo ago

@abbasrizi.bsky.social on stage talking about homophily within and across groups #CCS2025

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/

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

IC2S2'25 Norrköping - YouTube

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

youtube.com

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

AI & Public Health: Between Hype and Hope — with Samir Bahtt

YouTube video by Abbas K. Rizi

youtu.be