Ulysse Marquis
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ulyssemarquis.bsky.social
Ulysse Marquis
@ulyssemarquis.bsky.social
36 followers 95 following 15 posts
🔬 looking for order in messy systems
🌊🏙️ physics, cities, waves and maps
Posts Replies Media Videos
Reposted by Ulysse Marquis
rafaelprietocuriel.bsky.social
Large cities are often assumed to be more violent, but our review shows there’s nothing universal about urban violence.

In our new study, @ronaldomenezes.bsky.social and I show that isolated cities tend to experience higher rates of violence against civilians.

www.nature.com/articles/s41...
November 19, 2025 at 1:00 PM
Reposted by Ulysse Marquis
tiago.skewed.de
This level of blatant dishonesty baffles me. I'm seeing this more and more. Do people *want* to ruin their reputation?
casperalbers.nl Casper Albers 🟥 @casperalbers.nl · 16d
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...
screenshot from the paper, stating that no causal claims (like they did in the title) should be made. paper title
November 14, 2025 at 7:21 AM
ulyssemarquis.bsky.social
www.bbc.co.uk/weather/arti... www.lavoixdunord.fr/1645503/arti...
Northern Lights set to dazzle UK once again due to possible 'severe' geomagnetic storm
The Northern Lights have been shining over the UK and there is another chance to see them Wednesday as Elizabeth Rizzini and Helen Willetts explain.
www.bbc.co.uk
November 12, 2025 at 11:42 PM
ulyssemarquis.bsky.social
Great read journals.aps.org/rmp/abstract... (I also recommend the quick lecture as a teaser youtu.be/7WsMEL3Q0RI?...)
Statistical mechanics for networks of real neurons
Our ability to perceive, think, or act relies on coordinated activity in large networks of neurons in the brain. This review examines recent progress in connecting ideas from statistical physics, such...
journals.aps.org
November 12, 2025 at 7:45 PM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
Metros reduce car use in European cities but trams do not
https://arxiv.org/abs/2511.08280
November 12, 2025 at 3:46 PM
Reposted by Ulysse Marquis
hansonmark.bsky.social
We wrote the Strain on scientific publishing to highlight the problems of time & trust. With a fantastic group of co-authors, we present The Drain of Scientific Publishing:

a 🧵 1/n

Drain: arxiv.org/abs/2511.04820
Strain: direct.mit.edu/qss/article/...
Oligopoly: direct.mit.edu/qss/article/...
A table showing profit margins of major publishers. A snippet of text related to this table is below. 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year. A figure detailing the drain on researcher time. 1. The four-fold drain 1.2 Time The number of papers published each year is growing faster than the scientific workforce, with the number of papers per researcher almost doubling between 1996 and 2022 (Figure 1A). This reflects the fact that publishers’ commercial desire to publish (sell) more material has aligned well with the competitive prestige culture in which publications help secure jobs, grants, promotions, and awards. To the extent that this growth is driven by a pressure for profit, rather than scholarly imperatives, it distorts the way researchers spend their time. The publishing system depends on unpaid reviewer labour, estimated to be over 130 million unpaid hours annually in 2020 alone (9). Researchers have complained about the demands of peer-review for decades, but the scale of the problem is now worse, with editors reporting widespread difficulties recruiting reviewers. The growth in publications involves not only the authors’ time, but that of academic editors and reviewers who are dealing with so many review demands. Even more seriously, the imperative to produce ever more articles reshapes the nature of scientific inquiry. Evidence across multiple fields shows that more papers result in ‘ossification’, not new ideas (10). It may seem paradoxical that more papers can slow progress until one considers how it affects researchers’ time. While rewards remain tied to volume, prestige, and impact of publications, researchers will be nudged away from riskier, local, interdisciplinary, and long-term work. The result is a treadmill of constant activity with limited progress whereas core scholarly practices – such as reading, reflecting and engaging with others’ contributions – is de-prioritized. What looks like productivity often masks intellectual exhaustion built on a demoralizing, narrowing scientific vision. A table of profit margins across industries. The section of text related to this table is below: 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year. The costs of inaction are plain: wasted public funds, lost researcher time, compromised scientific integrity and eroded public trust. Today, the system rewards commercial publishers first, and science second. Without bold action from the funders we risk continuing to pour resources into a system that prioritizes profit over the advancement of scientific knowledge.
November 11, 2025 at 11:52 AM
Reposted by Ulysse Marquis
rmcelreath.bsky.social
How can we reform science? I have some ideas. But I am not sure you’ll like them, because they don’t promise much. elevanth.org/blog/2025/07...
Which Kind of Science Reform
What hope is there for science reform, if we can't agree on what to reform? Right now, principles are more important than practices.
elevanth.org
July 9, 2025 at 1:40 PM
ulyssemarquis.bsky.social
Our work on the dynamics of urban expansion just got published in the Physical Review Letters ! journals.aps.org/prl/abstract...
Universal Roughness and the Dynamics of Urban Expansion
Urban sprawl reshapes cities, yet its quantitative laws remain elusive. Analyzing built-up expansion in 19 cities (1985--2015) with tools from surface growth physics in radial geometry, we reveal anis...
journals.aps.org
October 31, 2025 at 2:26 PM
Reposted by Ulysse Marquis
freakonometrics.bsky.social
"In the 1940s, when the French mathematician Jacques Hadamard asked good mathematicians how they came up with solutions to hard problems, they nearly universally answered that they didn’t think in words; neither did they think in images or equations" www.henrikkarlsson.xyz/p/wordless-t...
When is better to think without words?
Non-verbal, blurry thinking is faster and can search in a broader way, but it is more error-prone than verbal thought.
www.henrikkarlsson.xyz
October 28, 2025 at 9:21 PM
Reposted by Ulysse Marquis
netscience.bsky.social
Principled Model Selection for Stochastic Dynamics link.aps.org/doi/10.1103/...
Principled Model Selection for Stochastic Dynamics
Complex dynamical systems, from macromolecules to ecosystems, are often modeled by stochastic differential equations. To learn such models from data, a common approach involves sparse selection among ...
link.aps.org
October 16, 2025 at 7:24 AM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
Modeling the spatial growth of cities
https://arxiv.org/abs/2510.03045
October 6, 2025 at 3:46 PM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
Universal Model of Urban Street Networks
https://arxiv.org/abs/2509.21931
September 29, 2025 at 3:45 PM
Reposted by Ulysse Marquis
danielhankim.bsky.social
Strikingly, the shortest-path percolation homogenizes scale-free networks before the phase transition, resulting in the same universality class as the Erdős–Rényi Networks!

Check out our new preprint on arXiv: arxiv.org/abs/2509.09142
Shortest-path percolation on scale-free networks
The shortest-path percolation (SPP) model aims at describing the consumption, and eventual exhaustion, of a network's resources. Starting from a graph containing a macroscopic connected component, ran...
arxiv.org
September 12, 2025 at 2:35 AM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
From lines to networks
https://arxiv.org/abs/2509.07951
September 10, 2025 at 3:46 PM
Reposted by Ulysse Marquis
diegorybski.bsky.social
Looks more complicated than it is. In our recent study journals.plos.org/plosone/arti... we search for an optimum city size, minimizing both urban carbon emissions and urban heat island (constraint: fundamental allometry). It turns out that given the known UHI parameters such optimum does not exist.
September 4, 2025 at 6:01 AM
Reposted by Ulysse Marquis
chub-fbk.bsky.social
Wide coverage of social media and disinformation analysis yesterday from our lab at the @css-conference.bsky.social, with four talks presenting our works associate to the European projects #AI4TRUST #AICODE_EU #HATEDEMICS
September 3, 2025 at 5:19 PM
Reposted by Ulysse Marquis
chub-fbk.bsky.social
Also seen yesterday at @css-conference.bsky.social a work on reinforcement learning applied to ants behaviour by Alessio Pitteri, our study of the historical evolution of EU projects by @verorsanigo.bsky.social and the study on Coordinated Behavior by @elisamurators.bsky.social #CCS2025
September 3, 2025 at 5:31 PM
ulyssemarquis.bsky.social
New pre-print out ! Work led by @eleandre.bsky.social, in collaboration with M. Napolitano and @ricgallotti.bsky.social. Using Foursquare data from Bologna, we find that the distribution of POIs follows a clear power-law pattern at the city scale. To explain this, we introduce a framework where ...
arxiv-soc-ph.bsky.social physics.soc-ph @arxiv-soc-ph.bsky.social · Sep 3
Scale-free Points-of-Interest Distribution in a City Emerging from Homogeneous Poissonian-point Processes
https://arxiv.org/abs/2509.01699
September 3, 2025 at 4:27 PM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
Scale-free Points-of-Interest Distribution in a City Emerging from Homogeneous Poissonian-point Processes
https://arxiv.org/abs/2509.01699
September 3, 2025 at 3:46 PM
Reposted by Ulysse Marquis
chub-fbk.bsky.social
Yesterday was our first day at @css-conference.bsky.social
in Siena 🇮🇹. We presented on Telegram data collection @elisamurators.bsky.social , city growth @ulyssemarquis.bsky.social and urban traffic (Alberto Amaduzzi). Excited for 5 more talks today! #CCS2025
September 2, 2025 at 7:22 AM
Reposted by Ulysse Marquis
alexvespi.bsky.social
Very interesting study on social contagion applied in a historical context by @szapperi.bsky.social and collaborators. Powerful example of where good historical data can lead us in the future.

www.nature.com/articles/s41...
Epidemiology models explain rumour spreading during France’s Great Fear of 1789 - Nature
Epidemiological methods are used to show that the Great Fear of 1789, a series of peasant insurrections in rural revolutionary France, was driven by deliberate political action rather than spontaneous...
www.nature.com
August 28, 2025 at 3:25 PM
Reposted by Ulysse Marquis
gro-tsen.bsky.social
Pour ce que ça vaut, je recopie ci-dessous un fil que j'ai posté sur Twitter en 2022, où je tente de raconter les bases fondamentales de la thermodynamique à tout le monde, d'une manière que j'espère pédagogique. 🧵⤵️ •1/24
July 3, 2025 at 7:17 PM
Reposted by Ulysse Marquis
mtizzoni.bsky.social
Opinion dynamics: Statistical physics and beyond

arxiv.org/abs/2507.11521
Opinion dynamics: Statistical physics and beyond
Opinion dynamics, the study of how individual beliefs and collective public opinion evolve, is a fertile domain for applying statistical physics to complex social phenomena. Like physical systems, soc...
arxiv.org
July 19, 2025 at 8:05 AM
Reposted by Ulysse Marquis
arxiv-soc-ph.bsky.social
Geometric Criticality in Scale-Invariant Networks
https://arxiv.org/abs/2507.11348
July 16, 2025 at 3:46 PM
Reposted by Ulysse Marquis
netscience.bsky.social
When dialects collide: how socioeconomic mixing affects language use epjdatascience.springeropen.com/articles/10....
When dialects collide: how socioeconomic mixing affects language use - EPJ Data Science
The socioeconomic background of people and how they use standard forms of language are not independent, as demonstrated in various sociolinguistic studies. However, the extent to which these correlati...
epjdatascience.springeropen.com
July 11, 2025 at 7:39 AM