Abbas K. Rizi
@abbasrizi.bsky.social
Networks, Epidemics & Social Behavior 🇩🇰
Postdoc Researcher at DTU Compute & SODAS
Editor-in-chief & Science Writer at sitpor.org
abbas.sitpor.org
Postdoc Researcher at DTU Compute & SODAS
Editor-in-chief & Science Writer at sitpor.org
abbas.sitpor.org
If you have an Iranian colleague or friend, this is likely how they feel theses days:
"When the internet is severed, the diaspora is not just worried; we are psychologically confused and helpless."
healthydebate.ca/2026/01/topi...
healthydebate.ca/2026/01/topi...
The deafening silence: A diaspora’s grief in the age of internet blackouts - Healthy Debate
For the Iranian diaspora, this is not a debate about policy reform; it's about survival. We need our governments and institutions to do more.
healthydebate.ca
January 27, 2026 at 4:17 PM
If you have an Iranian colleague or friend, this is likely how they feel theses days:
Reposted by Abbas K. Rizi
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 ... 😥😥
January 14, 2026 at 9:18 PM
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...
On Language & Poetry | A short post I wrote over the Christmas holidays; abbas.sitpor.org/2025/12/28/o...
December 28, 2025 at 11:57 AM
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...
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.
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 ...
www.nature.com
December 23, 2025 at 9:10 PM
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.
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.
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 🇺🇸
#Epidemics10 #NetSci2026 #CCS2026 #IC2S2 🇺🇸
December 3, 2025 at 4:11 PM
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 🇺🇸
#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.
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.
November 30, 2025 at 11:35 PM
“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.
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!
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...
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...
November 14, 2025 at 4:40 PM
What you expect the least from the reviewers and the editor is exactly checking for the main claims!
November 13, 2025 at 12:10 PM
“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 commenting on Nima's talk, Two Cheers for Shut Up and Calculate, at the Natural Philosophy Symposium 2025
November 2, 2025 at 11:03 AM
“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 commenting on Nima's talk, Two Cheers for Shut Up and Calculate, at the Natural Philosophy Symposium 2025
Reposted by Abbas K. Rizi
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...
Full call text and link to apply: www.aalto.fi/en/open-posi...
September 17, 2025 at 10:22 AM
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...
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
@elisamurators.bsky.social @cssociety.bsky.social
September 5, 2025 at 3:17 PM
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
@elisamurators.bsky.social @cssociety.bsky.social
Thank you for this opportunity. The slides of my talk & the preprint are available at abbas.sitpor.org
September 5, 2025 at 3:09 PM
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
“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
September 1, 2025 at 11:06 AM
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
“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
Reposted by Abbas K. Rizi
PNAS: Strength and weakness of disease-induced herd immunity in networks
https://www.pnas.org/doi/abs/10.1073/pnas.2421460122?af=R
https://www.pnas.org/doi/abs/10.1073/pnas.2421460122?af=R
August 15, 2025 at 1:12 PM
PNAS: Strength and weakness of disease-induced herd immunity in networks
https://www.pnas.org/doi/abs/10.1073/pnas.2421460122?af=R
https://www.pnas.org/doi/abs/10.1073/pnas.2421460122?af=R
August 1, 2025 at 12:54 PM
Reposted by Abbas K. Rizi
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.
www.youtube.com
July 25, 2025 at 3:49 PM
All the keynote recordings are available now, enjoy! www.youtube.com/playlist?lis...
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
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
July 23, 2025 at 12:41 PM
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
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
Reposted by Abbas K. Rizi
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.
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...
doi.org
July 19, 2025 at 4:50 PM
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.
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.
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
July 10, 2025 at 4:11 PM
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
Reposted by Abbas K. Rizi
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
arxiv.org/abs/2506.20623
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 ...
arxiv.org
July 10, 2025 at 9:49 AM
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
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.
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.
July 8, 2025 at 11:23 AM
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.
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.
Reposted by Abbas K. Rizi
My "Math, Revealed" series is freely available to anyone -- no paywall! -- in the thread below.
July 4, 2025 at 12:07 AM
My "Math, Revealed" series is freely available to anyone -- no paywall! -- in the thread below.
Reposted by Abbas K. Rizi
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...
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...
Dara
daracademy.dk
June 28, 2025 at 12:52 PM
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...
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...
Reposted by Abbas K. Rizi
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!
Also: currently looking for postdoc opportunities - happy to chat!
June 24, 2025 at 4:39 PM
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!
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 😄
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 😄
June 18, 2025 at 8:20 AM
@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 😄
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 😄