Ricard Alert Zenón
@ricardalert.bsky.social
ICREA Research Professor at Universitat de Barcelona. Research Group Leader at MPI-PKS and CSBD in Dresden. Theory of living matter. Collective phenomena in biology through the lens of active matter physics.
New paper! Inspired by gliding bacteria, we introduce active screws: Particles that self-propel by spinning around their propulsion axis. We show that active screws form active chiral nematics. With Debu Banerjee and @lauritzh.bsky.social @mpipks.bsky.social journals.aps.org/prresearch/a...
Our paper on a Hamiltonian description of non-reciprocal interactions is out @natphys.nature.com! With Yubo Shi, Roderich Moessner, and @marinbukov.bsky.social @mpipks.bsky.social @ub.edu @icreacommunity.bsky.social Check it out, and read more in the thread below! 👇 www.nature.com/articles/s41...
Hamiltonian description of non-reciprocal interactions - Nature Physics
Many active and driven systems exhibit non-reciprocal interactions, making them hard to describe with standard methods. Now a constrained Hamiltonian embedding with auxiliary variables reproduces thes...
nature.com
Ricard Alert Zenón@ricardalert.bsky.social · last yr.New preprint! Non-reciprocal interactions don’t arise from a potential. Yet, we found a way to encode them in a Hamiltonian, which captures the phase transitions of non-reciprocal systems! With Yubo Shi, Roderich Moessner, and @marinbukov.bsky.social @mpipks.bsky.social. arxiv.org/pdf/2505.05246
New preprint! Interested in mechanical interactions between cells and the extracellular matrix? We studied the feedback between cellular traction forces and the ECM nonlinear elasticity. With Irina Pi-Jaumà and Jaume Casademunt. arxiv.org/abs/2606.03669
Bistability of cellular traction on strain-stiffening substrates
To migrate, cells exert traction forces on the extracellular matrix (ECM) -- a biopolymer network that often exhibits nonlinear strain-stiffening elasticity. Cellular tractions can therefore stiffen t...
arxiv.org
Despite it being chaotic, active nematic turbulence can give rise to arrested labyrinthine patterns! Check out our new paper @physrevresearch.bsky.social! Work led by Ido Lavi, with Jean-François Joanny and Jaume Casademunt. journals.aps.org/prresearch/a...
📰 Notícies, agenda científica, descobriments i entrevistes. ICREA't és el teu nou portal per seguir l'actualitat de les investigacions dels recercaires ICREA a Catalunya. No et perdis res 👉 icreat.cat
New preprint! We show how mesoscopic nonequilibrium fluctuations in active gels emerge from the breaking of detailed balance at the molecular scale. Warning: Long technical paper ahead! Enjoy! @mpipks.bsky.social @ub.edu @ubics.bsky.social @icreacommunity.bsky.social arxiv.org/abs/2601.20483
#NousICREAs2025 | 🧬 Ricard Alert @ricardalert.bsky.social (@ub.edu) investiga en física biològica. Estudia com les lleis de la física governen la vida, per exemple, investigant com cèl·lules i bacteris es mouen en grups. short.do/UBTLe-
Our paper on the transition to active turbulence is now out @natcomms.nature.com! With @the-chaotician.bsky.social. Are you curious how activity begets chaos? Check out the paper and the thread below. 👇 www.nature.com/articles/s41...
Discontinuous transition to active nematic turbulence - Nature Communications
Active fluids, such as bacterial suspensions, exhibit chaotic flows at low Reynolds number - a phenomenon known as active turbulence. Here, the authors show a discontinuous transition from laminar to ...
nature.com
Ricard Alert Zenón@ricardalert.bsky.social · 2y agoNew preprint! When and how do active flows become turbulent? We found that, in unconfined active nematics, the transition to turbulence is discontinuous! With @the-chaotician.bsky.social @mpipks.bsky.social arxiv.org/abs/2501.060...
New preprint! Do you like ocean waves? We found similar waves on bacterial colonies! We found that this collective behavior, known as rippling, is nothing but surface waves on an active nematic. @princeton.edu @mpipks.bsky.social @ub.edu @icreacommunity.bsky.social www.biorxiv.org/content/10.1...
Super excited to start as an ICREA Research Professor at the University of Barcelona! Really happy to join fantastic colleagues at @icreacommunity.bsky.social and @ub.edu. www.icrea.cat/community/ic...
ICREAs Fitxa - ICREA
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🎧🎙Últim capítol de La utilitat del coneixement inútil! Parlem amb la @gmarfanyn.bsky.social sobre CRISPR i obrim el debat que hem de tenir tots de la millor manera: amb el coneixement científic a la mà! @soctastaolletes.bsky.social youtu.be/DUzzjkkUBT4?...
T1C7 Els bacteris, l’edició genètica i el Nobel robat, amb Gemma Marfany i Nadal
YouTube video by La Dimoni de Maxwell
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Active droplets are fundamental in cell biology and origin of life. With Jonathan Bauermann, @boekhovenlab.bsky.social, Frank Jülicher, and @m-pol.bsky.social, we show that a critical transition influences their size, morphology, ripening and division propensity journals.aps.org/prx/abstract...
🕵️ A qui t’agradaria conèixer? Amb quantes persones hi arribaries? El Ricard Solé @ricardsole.bsky.social, investigador ICREA a @upf.edu ens ho explica al nostre pòdcast! youtube.com/shorts/buG_R...
6 graus de separació #ciènciaencatalà #podcast #divulgaciócientífica #ciència
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Escolta en nou capítol de La utilitat del coneixement inútil! Quàntica, ordinadors i espanta sogres!!! 🎉🥳
Cèlia Ventura i Gabarró@soctastaolletes.bsky.social · 10mo agoNou capítol! 🔴 Parlem de quàntica i superordinadors, la @marionamec.bsky.social em peta la neurona, l'Alba Cervera ens explica què fa al @bsc-cns.bsky.social i descobrim que els espanta-sogres poden ser molt pesats 🥳 Amb la suport de la @fcri.bsky.social 💜 open.spotify.com/episode/6wJL...
🤔 Can tissue patterning & tumor heterogeneity emerge in a self-organized way? We show that self-organized mechanical stress & density gradients pattern tumors in vitro & in vivo, and this behavior is quantitatively predicted by a mechano-chemical active fluid model! Check out Carlos' thread ⬇️
Carlos Pérez-González@cperez-gonzalez.bsky.social · 10mo ago1/ 🎉Excited to share our new preprint @vignjeviclab.bsky.social @davidbrueckner.bsky.social : "Self-organization of tumor heterogeneity and plasticity" biorxiv.org/content/10.1... Tumor heterogeneity and plasticity drive metastasis and relapse. How is tumor patterning coordinated? A thread👇
1/ 🎉Excited to share our new preprint @vignjeviclab.bsky.social @davidbrueckner.bsky.social : "Self-organization of tumor heterogeneity and plasticity" biorxiv.org/content/10.1... Tumor heterogeneity and plasticity drive metastasis and relapse. How is tumor patterning coordinated? A thread👇
🛰️ Sabies que fas servir la teoria de la relativitat cada cop que treus el GPS? Mira el 4t capítol de La utilitat del coneixement inútil per veure com li peta el cap a la @soctastaolletes.bsky.social 🤯 Amb un ajut @fcri.bsky.social open.spotify.com/episode/4lza...
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New job, new preprint! We found that embryo implantation can be understood as active wetting! Embryos from older mothers have trouble implanting because they are too contractile and viscous. Check out the wonderful thread (and movies!) by @katecavanaugh.bsky.social. www.biorxiv.org/content/10.1...
A mechanical origin for implantation defects in embryos from aged females
Women over 35 experience a marked reduction in fertility. The origin of these fertility defects appears to reside in the implantation capacity of the embryo itself, but the mechanistic basis of this i...
biorxiv.org
Kate Cavanaugh@katecavanaugh.bsky.social · 11mo agoSee this? This = implanting mouse embryo. Usually this happens inside its mother and is invisible to us, but we can actually watch implantation ex vivo with the hope of understanding why implantation goes awry in embryos of older women. A 🧵...
Warm goodbye to Dresden's @mpipks.bsky.social, my scientific home for the past 4 years. It's been amazing to start my group here! Thanks to the Max Planck Society, group members and everyone at the institute! Looking forward to the new chapter in Barcelona @ub.edu
IG Nobel Prize in #Physics 2025 to @mpipks.bsky.social researchers for elucidating the phase behaviour of cacio e pepe sauce. The work highlights how physics can also be applied to solve daily-life problems! nature.com/articles/d41586-025-03045-0
Tipsy bats and perfect pasta: Ig Nobels celebrate ‘improbable’ research
The annual awards are a celebration of weird but thought-provoking science.
nature.com
Truly happy to see that our Italian colleagues @mpipks.bsky.social won the IgNobel Prize for figuring out that the Cacio e Pepe sauce can easily phase separate and become clumpy! Very well deserved! Congrats to the team! 😀
Max-Planck-Gesellschaft@maxplanck.de · 11mo agoTruly chuffed for our fearless food physicists @mpipks.bsky.social + collabs from AT @istaresearch.bsky.social, IT & ES who won this year’s Ig Nobel - the #NobelPrize of hearts❤️for cracking the science of perfect pasta !🍝Kudos to all for intrepidly consuming lots of cheese in the name of science!😋
Check our new preprint on active surface simulations of amoeboid migration! We show how this mode of migration can be mechanically guided by gradients in friction, viscosity, pressure, or confinement, and even by nearby cells. Work led by Hanna Gertack and Sebastian Aland. arxiv.org/abs/2509.11801
🤔Què tenen en comú l’Ou com balla i un àtom? 🎙️El Lluís Torner, fundador de l’ICFO ens ho explica! 👉 Escolta el 2n capítol de La utilitat del coneixement inútil! Amb el suport d’un Ajut FCRI 2025 @fcri.bsky.social @soctastaolletes.bsky.social youtube.com/shorts/Al5mY...
L'àtom com balla!
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Very honored to receive this prize from the Spanish Physical Society! Thanks a lot to all my collaborators, who make this possible!
Max Planck Institute for the Physics of Complex Systems@mpipks.bsky.social · 11mo agoCongratulations to @ricardalert.bsky.social on being awarded the "Young Investigator Prize in Theoretical Physics” by the Spanish Royal Academy of Physics and the BBVA Foundation! The award is in recognition of his contributions to biological physics. www.fbbva.es/noticias/fal...
Bacteria are surrounded by water! New work @natphys.nature.com by @ricardalert.bsky.social @mpipks.bsky.social & collaborators @ Princeton University shows that water capillary forces organise bacterial colonies into gas, nematic streams, and droplet states. nature.com/articles/s41567-025-02965-y
Our paper about active crystals is now out @softmatter.rsc.org! During the revisions, we added a section about triangular lattices, on which the turn-towards or turn-away interactions can be frustrated. Check it out, and see the post below! pubs.rsc.org/en/content/a... bsky.app/profile/rica...
Lattice-dependent orientational order in active crystals
Via mechanisms not accessible at equilibrium, self-propelled particles can form phases with positional order, such as crystals, and with orientational order, such as polar flocks. However, the interpl...
pubs.rsc.org
Ricard Alert Zenón@ricardalert.bsky.social · last yr.New preprint! When forming a crystal, active particles that turn either towards or away from each other end up aligning along directions determined by the crystalline lattice. In these active crystals, orientational and positional order are coupled. Work by Till Welker! arxiv.org/abs/2506.16501
Has intentat ma fer un gelat casolà i no ha sortit tan cremós com esperaves? T'han quedat uns cristalls que et trinxen les dents? 🍦☀️ A la @soctastaolletes.bsky.social i a mi ens ha passat, però tenim la solució... youtube.com/shorts/hAXjP...
Gelat de vidre
YouTube video by La Dimoni de Maxwell
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Dreaming of a swimming pool? Bacteria are surrounded by water! Water capillary forces organize bacterial colonies into gas, nematic streams, or droplet states. New paper @natphys.nature.com led by Matt Black and Chenyi Fei, with Ned Wingreen and Josh Shaevitz! www.nature.com/articles/s41...
Capillary interactions drive the self-organization of bacterial colonies - Nature Physics
Bacteria tend to live in thin layers of water on surfaces. Now the capillary forces in these layers are shown to help organize the bacteria into dense packs.
nature.com
New preprint! When forming a crystal, active particles that turn either towards or away from each other end up aligning along directions determined by the crystalline lattice. In these active crystals, orientational and positional order are coupled. Work by Till Welker! arxiv.org/abs/2506.16501
Lattice-dependent orientational order in active crystals
Via mechanisms not accessible at equilibrium, self-propelled particles can form phases with positional order, such as crystals, and with orientational order, such as polar flocks. However, the interpl...
arxiv.org
