Advertisement · 728 × 90

Posts by Kleber Oliveira

New system states introduced with the parameter μ. The same parameterization except for different innovation probability μ can lead to consensus in a homogeneous topology or two polarized communities. On the left, the innovation probability μ = 1. On the right, μ = 0.1.

New system states introduced with the parameter μ. The same parameterization except for different innovation probability μ can lead to consensus in a homogeneous topology or two polarized communities. On the left, the innovation probability μ = 1. On the right, μ = 0.1.

Social media sites can bring people together or push them further apart. A modeling study shows how small changes in posting or recommendation rules can flip a system from consensus to polarization. In PNAS Nexus: https://ow.ly/hLrY50Y3KPk

2 months ago 5 3 0 0
Preview
Mechanistic interplay between information spreading and opinion polarization Abstract. We investigate how information-spreading mechanisms affect opinion dynamics and vice versa via an agent-based simulation on adaptive social netwo

We link virality and polarization. An ABM calibrated on Brexit and Vaccine debates shows the same parameters that generate cascades also generate polarized opinions. Thanks to @ymoreno.bsky.social and @kleber-ao.com
academic.oup.com/pnasnexus/ar...

2 months ago 5 3 0 0
Un estudio del BIFI-UNIZAR arroja nuevos datos sobre el fenómeno de polarización en redes sociales online

Para quienes habláis español: si queréis saber más sobre la polarización y la difusión de información en redes sociales, aquí tenéis una nota de prensa sobre nuestro estudio reciente.
www.unizar.es/actualidad/v...
@ymoreno.bsky.social and @kleber-ao.com
www.unizar.es/actualidad/v...

2 months ago 4 1 0 0

Come and do a PhD at Exeter with me and Chico Camargo (Computer Science) on human-genAI coevolution

"Leveraging Natural Language Processing for Data-Driven Agent-Based Modelling of Online Cultural Dynamics"

www.exeter.ac.uk/v8media/recr...

More details here:
www.exeter.ac.uk/study/fundin...

5 months ago 19 26 1 0
How to Apply to the Graduate Program

One week left to apply to the UVA Biology PhD program! If you or someone you know are interested in contagion from a complex systems perspective, please reach out! I'm looking for a grad student! bio.as.virginia.edu/how-apply-gr...

4 months ago 7 11 2 0

I think the shortest version of why LLMs are an anti education technology is that education is fundamentally about making shared context to understand ourselves, each other, and the world

And by design LLMs destroy shared context

4 months ago 1476 383 29 25
Preview
Meta and TikTok are obstructing researchers’ access to data, European Commission rules Data are needed to study how social media spreads misinformation and influences elections, scientists say

"Access to data by researchers is a crucial element of ensuring transparency and democratic accountability,” @lewan.bsky.social says. “The public is entitled to know what platforms and their algorithms are doing to the information landscape.”
I wrote for @science.org about Meta, TikTok and the DSA 🧪

5 months ago 66 40 3 4
Preview
The Physics of News, Rumors, and Opinions The boundaries between physical and social networks have narrowed with the advent of the Internet and its pervasive platforms. This has given rise to a complex adaptive information ecosystem where ind...

arXiv alert! 📄🚨
A review paper about the physics of news, rumors, and opinions
arxiv.org/abs/2510.15053
w @manlius.bsky.social @sarawalk.bsky.social Guido Cadarelli et al.

6 months ago 16 7 0 0
An illustration of me, and the headline: "AI agents are coming for your privacy, warns Meredith Whittaker
The Signal Foundation’s president worries they will also blunt competition and undermine cyber-security"

An illustration of me, and the headline: "AI agents are coming for your privacy, warns Meredith Whittaker The Signal Foundation’s president worries they will also blunt competition and undermine cyber-security"

To put it bluntly, the path currently being taken towards agentic AI leads to an elimination of privacy and security at the application layer. It will not be possible for apps like Signal—the messaging app whose foundation I run—to continue to provide strong privacy guarantees, built on robust and openly validated encryption, if device-makers and OS developers insist on puncturing the metaphoric blood-brain barrier between apps and the OS. Feeding your sensitive Signal messages into an undifferentiated data slurry connected to cloud servers in service of their AI-agent aspirations is a dangerous abdication of responsibility.

To put it bluntly, the path currently being taken towards agentic AI leads to an elimination of privacy and security at the application layer. It will not be possible for apps like Signal—the messaging app whose foundation I run—to continue to provide strong privacy guarantees, built on robust and openly validated encryption, if device-makers and OS developers insist on puncturing the metaphoric blood-brain barrier between apps and the OS. Feeding your sensitive Signal messages into an undifferentiated data slurry connected to cloud servers in service of their AI-agent aspirations is a dangerous abdication of responsibility.

Happily, it’s not too late. There is much that can still be done, particularly when it comes to protecting the sanctity of private data. What’s needed is a fundamental shift in how we approach the development and deployment of AI agents. First, privacy must be the default, and control must remain in the hands of application developers exercising agency on behalf of their users. Developers need the ability to designate applications as “sensitive” and mark them as off-limits to agents, at the OS level and otherwise. This cannot be a convoluted workaround buried in settings; it must be a straightforward, well-documented mechanism (similar to Global Privacy Control) that blocks an agent from accessing our data or taking actions within an app.

Second, radical transparency must be the norm. Vague assurances and marketing-speak are no longer acceptable. OS vendors have an obligation to be clear and precise about their architecture and what data their AI agents are accessing, how it is being used and the measures in place to protect it.

Happily, it’s not too late. There is much that can still be done, particularly when it comes to protecting the sanctity of private data. What’s needed is a fundamental shift in how we approach the development and deployment of AI agents. First, privacy must be the default, and control must remain in the hands of application developers exercising agency on behalf of their users. Developers need the ability to designate applications as “sensitive” and mark them as off-limits to agents, at the OS level and otherwise. This cannot be a convoluted workaround buried in settings; it must be a straightforward, well-documented mechanism (similar to Global Privacy Control) that blocks an agent from accessing our data or taking actions within an app. Second, radical transparency must be the norm. Vague assurances and marketing-speak are no longer acceptable. OS vendors have an obligation to be clear and precise about their architecture and what data their AI agents are accessing, how it is being used and the measures in place to protect it.

📣 NEW -- In The Economist, discussing the privacy perils of AI agents and what AI companies and operating systems need to do--NOW--to protect Signal and much else!

www.economist.com/by-invitatio...

7 months ago 876 281 12 31
Advertisement
Open Letter: Stop the Uncritical Adoption of AI Technologies in Academia

Uncritical adoption of AI “undermines our basic pedagogical values and principles of scientific integrity. It prevents us from maintaining our standards of independence & transparency. And most concerning, AI use … hinder[s] learning and deskill critical thought.” openletter.earth/open-letter-...

8 months ago 130 55 2 10

"The order, aggravated by Trump's illegal attempt on intervening on Brazil's sovereign institutions, comes before..." -- there you go, corrected it for you in case you have any spine left and would call it as is

9 months ago 1 0 0 0
Post image

We ran a randomized controlled trial to see how much AI coding tools speed up experienced open-source developers.

The results surprised us: Developers thought they were 20% faster with AI tools, but they were actually 19% slower when they had access to AI than when they didn't.

9 months ago 6894 3011 109 623
Preview
Trump's Dictator Protection Program Using tariffs to fight democracy

With everything else going on, I'm not sure people realize that Trump's latest tariff on Brazil took things to a new (lower) level
paulkrugman.substack.com/p/trumps-dic...

9 months ago 1254 377 61 38

This is awful... 🤦

10 months ago 1 0 0 0

Funny thing, "there are many Brazilians on this platform" exactly because another platform refused to comply with the most basic things to operate in the country, such as having legal representation.

Maybe we wait and see on this one before announcing it's the death of social media?

10 months ago 0 0 0 0

the Brazilian replies to this post will take you on a fucking journey

10 months ago 2004 429 50 28

Well done, @arifosch.bsky.social

10 months ago 2 0 0 0
Post image

If you're looking for a quite handy multitype branching process framework for modeling diffusion in networks with communities check this work by @davidjpos.bsky.social and friends. @netsciconf.bsky.social #netsci2025

10 months ago 6 2 1 0

Fully-funded PhD positions to work with a fantastic team (and me 🫠) in a beautiful campus. Please share it with people who may be interested! Deadline on the 10th of July.

10 months ago 2 1 0 0
Advertisement
Post image

We often suppose that things like intelligence and opinions not only exist, but can be measured in a “correct” way. So our goal is to reduce the error as much as possible to get closer and closer to such “correct” measurement. [1/7]

11 months ago 3 2 1 0

On top of leaning towards this with the usual networks + nonlinear dynamics toolkit (I suppose I will be able to call myself a computational social scientist at some stage?), we will deal with a good amount of information theory. Feel free to reach out if you are curious about the project's details!

11 months ago 3 0 0 0

Glad to share that next month I am joining @mikeq.bsky.social's group on a full-time research position in my alma mater.

I've been studying social systems for some time, but never from the theoretical foundations of how people act towards each other (which are from social psychology).

11 months ago 2 0 1 0
Preview
Trump’s team, often accused of spreading misinformation, slashes misinformation research Hundreds of grants axed in a field where the United States was a global leader

Good piece in Science by @kakape.bsky.social on the massive censorship of scientific work by the U.S. government - all in the name of free speech, presumably: www.science.org/content/arti...

11 months ago 20 11 1 1

I am really glad I had the opportunity to work with co-authors who are so knowledgeable on the topic. Thanks very much @pietrotraversa.bsky.social @ymoreno.bsky.social and @guifarruda.bsky.social for the amazing work. Be sure to check the pre-print.

11 months ago 1 0 0 0

Our comparison of the model against empirical data also provides additional evidence that real-world rumor propagation tends to occur near criticality, opening the door to a more detailed understanding of rumor dynamics in Higher-order systems. 4/5

11 months ago 1 0 1 0

Interestingly, our analysis reveals continuous transitions in both homogeneous and heterogeneous hypergraphs, challenging the idea that higher-order interactions necessarily lead to discontinuous transitions. 3/5

11 months ago 1 0 1 0

and then compare it with empirical rumour cascades reconstructed from Telegram and a dataset of e-mail threads. We show that the model has two distinct subcritical behaviors that can coexist. 2/5

11 months ago 1 0 1 0
Preview
Rumor propagation on hypergraphs The rapid spread of information and rumors through social media platforms, especially in group settings, motivates the need for more sophisticated models of rumor propagation. Traditional pairwise mod...

Now out: "Rumor propagation on hypergraphs" (arxiv.org/abs/2504.19305). We propose a higher-order rumour model incorporating a group-based annihilation mechanism. We run computational experiments to characterise the model's dynamics in synthetic and real systems... 1/5

11 months ago 7 3 1 0
Post image

PhD Timeline xkcd.com/3081

11 months ago 60060 20550 590 831
Advertisement
Preview
Postdoctoral Researcher (f/m/d) Postdoctoral Researcher (f/m/d)

Are you interested in inequalities, mobility and cities? Come to work with us as a postdoc at @ceu-dnds.bsky.social in Vienna in the Computational Human Dynamics Lab of @martonkarsai.bsky.social. Check the post here: careers.ceu.edu/job/Vienna-P...

@ic2s2.bsky.social @netscisociety.bsky.social

11 months ago 11 8 0 0