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David Yllanes

@davidyllanes.bsky.social
87 followers 142 following 36 posts

Físico teórico en BIFI-ZCAM (Unizar), aficionado a la historia y operófilo viajero. Statistical mechanics, complex systems, biophysics, wargames and opera.

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Reposted by David Yllanes
Club Batallador @clubbatallador.bsky.social · 19/03/2026
#Batalladores2026 tendrá lugar en Zaragoza, del 19 al 22 de noviembre de 2026. La esperada cita anual de juegos de simulación histórica volverá a reunir 350 participantes de toda España y otros países Muy pronto, más detalles sobre inscripciones, programa y actividades. #Batalladores
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David Yllanes @davidyllanes.bsky.social · 13/02/2026
Registration is open for our CECAM Flagship School on Machine Learning–Assisted Sampling, to be held in Zaragoza (Spain) on June 15-19. The lectures will cover advanced methods at the interface of statistical physics, machine learning and computational sampling. www.cecam.org/workshop-det...
Poster for the CECAM School on Machine Learning–Assisted Sampling, June 15-19 at ZCAM in Zaragoza (Spain).

Registration deadline: March 9, 2026.

Lecturers:
Federico Ricci-Tersenghi (Auto-Regressive Models) - Sapienza University of Rome (IT)
Miguel Ruiz-García (Learning Dynamical Laws from Trajectories Using GNNs) - Universidad Complutense de Madrid (ES)
Zakari Denis (Neural Networks for Quantum-System Simulation - Max Planck Institute for the Science of Light (DE)
Roger Guimerá (Learning Mathematical Models for Inference) - ICREA, Universitat Rovira i Virgili (ES)
Xavier Waintal (Tensor Networks) - CEA Grenoble (FR)

Organisers:
Elisabeth Agoritsas
Aurélien Decelle (Universidad Politécnica de Madrid)
Daniel Matoz (Complutense University of Madrid)
Beatriz Seoane (Universidad Complutense de Madrid)
David Yllanes (Universidad de Zaragoza)
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David Yllanes @davidyllanes.bsky.social · 31/12/2025
Lo más jugado por mí en 2025. Ha sido un año de varias campañas largas (GTS, OCS y otros sistemas) y, por ello, con menos novedades que otros. Aún así, 39 juegos diferentes y partidas compartidas con 51 jugadores. Reencuentro con las miniaturas con un torneo de FoW v3.
Mis juegos más jugados en 2025 (en tiempo):

83h: The Greatest Day: Utah Beach;
42h: The Third Winter: The Battle for the Ukraine September 1943-April 1944;
33h: Advanced Squad Leader;
26h: The Jaws of Victory: Battle of Korsun-Cherkassy Pocket – January/February 1944;
24h: Brazen Chariots: Battles for Tobruk, 1941;
23h: Atlantic Chase: The Kriegsmarine Against the Home Fleet 1939-1942;
15h: France '40: 2nd Edition;
13h: John Company: Second Edition;
10h: Undaunted 2200: Callisto;
9h: Arcs: The Blighted Reach Expansion;
9h: Europe in Turmoil: Prelude to the Great War;
9h: Europe in Turmoil II: The Interbellum Years 1920-1939;
9h: Hungarian Rhapsody: The Eastern Front in Hungary;
8h: Storm Over Jerusalem: The Roman Siege;
7h: Angola;
6h: Flames of War: The World War II Miniatures Game.
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Reposted by David Yllanes
David Yllanes @davidyllanes.bsky.social · 23/12/2025
Our joint experimental-theoretical review of spin-glass dynamics is now published in Reviews of Modern Physics. The last couple of decades have seen major progress, culminating with the joint quantitative analysis of memory and rejuvenation in experiment and simulation.
Illustration of the order parameter for spin glasses.

Below the critical temperature, spins freeze collectively. There is no long-range magnetic order, though, as illustrated in the two left panels, which show configurations of two real replicas of the same spin glass. These have evolved for a long time in the broken-symmetry phase in a Monte Carlo simulation. The color map shows the average magnetization in the XY plane, averaged over the Z axis, which is always zero. 

If, instead, we plot the overlap between both replicas (right panel) a clear pattern emerges, with slowly growing glassy domains.Temperature chaos, a strong sensitivity of the spin-glass state to temperature changes, is now understood to be at the root of the rich dynamical effects that spin glasses experience in temperature-varying protocols.

Chaos is, however, an elusive effect, that defied numerical efforts to characterise it for a long time. In a nonequilibrium setting, much of the reason is its highly heterogeneous nature. The figure depicts a set of small spherical regions within the same spin-glass sample. These are coloured according to their chaoticity parameter, showing that only small areas of the system are strongly chaotic.

One consequence of these dynamical heterogeneities is that multiple length scales have to be studied in order to explain experimental effects such as memory and rejuvenation.
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David Yllanes @davidyllanes.bsky.social · 23/12/2025
Our joint experimental-theoretical review of spin-glass dynamics is now published in Reviews of Modern Physics. The last couple of decades have seen major progress, culminating with the joint quantitative analysis of memory and rejuvenation in experiment and simulation.
Illustration of the order parameter for spin glasses.

Below the critical temperature, spins freeze collectively. There is no long-range magnetic order, though, as illustrated in the two left panels, which show configurations of two real replicas of the same spin glass. These have evolved for a long time in the broken-symmetry phase in a Monte Carlo simulation. The color map shows the average magnetization in the XY plane, averaged over the Z axis, which is always zero. 

If, instead, we plot the overlap between both replicas (right panel) a clear pattern emerges, with slowly growing glassy domains.Temperature chaos, a strong sensitivity of the spin-glass state to temperature changes, is now understood to be at the root of the rich dynamical effects that spin glasses experience in temperature-varying protocols.

Chaos is, however, an elusive effect, that defied numerical efforts to characterise it for a long time. In a nonequilibrium setting, much of the reason is its highly heterogeneous nature. The figure depicts a set of small spherical regions within the same spin-glass sample. These are coloured according to their chaoticity parameter, showing that only small areas of the system are strongly chaotic.

One consequence of these dynamical heterogeneities is that multiple length scales have to be studied in order to explain experimental effects such as memory and rejuvenation.
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Reposted by David Yllanes
Morgane Gouyon-Rety @morganegr.bsky.social · 23/11/2025
At the invitation of the organization team (which includes one of my star beta testers, @davidyllanes.bsky.social, I got to present my new game @gmtgames.bsky.social Hubris - Twilight of the Hellenistic World, which was a ton of fun for the players and myself!
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Reposted by David Yllanes
Morgane Gouyon-Rety @morganegr.bsky.social · 23/11/2025
Back home tired but delighted after a wonderful 4-days trip to Zaragoza to attend the top notch Batalladores 2025 convention masterfully organized by @clubbatallador.bsky.social So impressed, and not a little jealous, by the super dynamic ConSim community in Spain.
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David Yllanes @davidyllanes.bsky.social · 23/11/2025
¡Gracias a todos por venir a #Batalladores2025 y os esperamos el año que viene! @clubbatallador.bsky.social
Foto de conjunto de la organización de la convención de juegos de simulación histórica Batalladores 2025.
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David Yllanes @davidyllanes.bsky.social · 30/07/2025
Happy to report that our project "From Neural Networks to Proteins: Modelling Complexity Through Spin-Glass Physics" is being funded by the Spanish MICIU. Especially since this is a UCM-Unizar coordinated grant, whose Madrid PI is my friend and long-time collaborator @betapata.bsky.social.
The co-PIs in more carefree times, attending the 2013 Statphys conference in Seoul as postdocs from La Sapienza Università di Roma.
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David Yllanes @davidyllanes.bsky.social · 06/04/2025
Ya tenemos montado el mapa y todas las plantillas y registros para la gran campaña del GTS de Utah de MMP en el Club Dragón de Madrid. Mucho bocage que atravesar. Luce estupendo en la mesa el mapa de Nicolás Eskubi. Ahora a empezar con las fichas.
Vista general del mapa de la campaña completa de Utah (siete piezas). La playa de desembarco se aprecia en la esquina superior derecha. El área cubierta atraviesa la península de Cotentin, una zona cubierta de terreno difícil y denso. Alrededor, las plantillas de las seis divisiones alemanas y las cinco estadounidenses y del apoyo naval y de cuerpo, así como el registro de turnos y diversas tablas.Ampliación de la zona de desembarco.Otra perspectiva de la vista general, con las divisiones alemanas y las tablas de terreno en primer plano.Esquema de la disposición de los mapas individuales para la campaña. El juego incluye también multitud de escenarios que utilizan solo parte de la zona (por ejemplo, asaltos paracaidistas en Ste.-Mère-Église o simulación exclusivamente del desembarco en la playa, pero también encuentros en otras zonas del mapa a largo de las dos semanas de campaña).
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David Yllanes @davidyllanes.bsky.social · 16/03/2025
Mi primera visita a la Staatsoper Stuttgart. En cartel, «El jugador» de Prokófiev. Aušrinė Stundytė, Goran Jurić, Daniel Brenna, Véronique Gens.
Fachada de la ópera de Stuttgart poco antes de la función el 15 de marzo de 2025.Cartel de «El jugador» («Игрок») de Prokófiev.Antes de la función, sobre el telón bajado se proyecta una carta de Alekséi a Polina en inglés, alemán y ruso.Interior de la ópera de Stuttgart antes de la función.
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Reposted by David Yllanes
David Yllanes @davidyllanes.bsky.social · 03/03/2025
Fin de semana en la Oper Frankfurt que demuestra perfectamente las singulares fortalezas de esta compañía. Dos nuevas producciones de obras muy difíciles de ver que combinan de maravilla y funciones que descansan sobre su excelente grupo de cantantes de ensemble y sobre sus cuerpos estables.
David Yllanes entre los carteles de «Guercœur» y «Le Postillon de Lonjumeau», dos nuevas producciones de la Oper Frankfurt vistas este fin de semana.Saludos finales del «Guercœur». Se aprecia al fondo el escenario que muestra el edificio del Parlamento, derrumbado al final del segundo acto. Domen Križaj, AJ Glueckert y Claudia Mankhe lideran el el reparto, con dirección musical de Marie Jacquot y escénica de David Hermann.Römerberg de Fráncfort preparada para el desfile del domingo de Carnaval.
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David Yllanes @davidyllanes.bsky.social · 03/03/2025
Fin de semana en la Oper Frankfurt que demuestra perfectamente las singulares fortalezas de esta compañía. Dos nuevas producciones de obras muy difíciles de ver que combinan de maravilla y funciones que descansan sobre su excelente grupo de cantantes de ensemble y sobre sus cuerpos estables.
David Yllanes entre los carteles de «Guercœur» y «Le Postillon de Lonjumeau», dos nuevas producciones de la Oper Frankfurt vistas este fin de semana.Saludos finales del «Guercœur». Se aprecia al fondo el escenario que muestra el edificio del Parlamento, derrumbado al final del segundo acto. Domen Križaj, AJ Glueckert y Claudia Mankhe lideran el el reparto, con dirección musical de Marie Jacquot y escénica de David Hermann.Römerberg de Fráncfort preparada para el desfile del domingo de Carnaval.
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David Yllanes @davidyllanes.bsky.social · 12/01/2025
Hoy ha tocado «Der Kreidekreis» de Zemlinsky, compositor que debería poder verse mucho más, en la Deutsche Oper am Rhein de Düsseldorf. Antes, visita al pequeño pero muy apañado Filmmuseum Düsseldorf.
Interior de la Opernhaus Düsseldorf antes de empezar la función.Mesa de montaje original que utilizó Lotte Reiniger en su etapa en la BBC en los años 50, parte de una completa exposición permanente sobre la directora.Maqueta que recrea el sistema empleado por Méliès para crear el efecto de una cabeza hinchable en «El hombre de la cabeza de goma».
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David Yllanes @davidyllanes.bsky.social · 12/01/2025
Deliciosa «Čert a Káča» («El diablo y Catalina», Dvořák) en el Teatro Nacional de Praga. Una divertida y vistosa producción con una estética de ilustración infantil que refuerza su carácter de cuento de hadas.
Saludos al final de la función. Se aprecian algunos de los diseños del ilustrador Alfred Born.Interior del Teatro Nacional de Praga, todavía sin público antes de empezar la función.Vista del río Moldova y del puente de Carlos, con el castillo de Praga asomando al fondo.La torre de la Pólvora por la noche.
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David Yllanes @davidyllanes.bsky.social · 09/01/2025
Our first paper of 2025 is now published (open access) on Physical Review Research (doi.org/10.1103/Phys...) We present a method to generate Markov-chain trajectories constrained to an initial and a final state (Markov bridges), which we apply to scRNA data to study cell-differentiation pathways.
We present a method to sample Markov-chain trajectories constrained to both the initial and final conditions, which we term Markov bridges. The trajectories are conditioned to end in a specific state at a given time. We derive the master equation for Markov bridges, which exhibits the original transition rates scaled by a time-dependent factor. Trajectories can then be generated using a refined version of the Gillespie algorithm. We illustrate the benefits of our method by sampling trajectories in the Müller-Brown potential. This allows us to generate transition paths which would otherwise be obtained at a high computational cost with standard kinetic Monte Carlo methods because commitment to a transition path is essentially a rare event. We then apply our method to a single-cell RNA sequencing dataset from mouse pancreatic cells to investigate the cell differentiation pathways of endocrine-cell precursors. By sampling Markov bridges for a specific differentiation pathway, we obtain a time-resolved dynamics that can reveal features such as cell types which behave as bottlenecks. The ensemble of trajectories also gives information about the fluctuations around the most likely path. For example, we quantify the statistical weights of different branches in the differentiation pathway to alpha cells.Markov bridges for the pancreas dataset, with 
N = 3696, αi = 1103  (ductal state) and tf = 100. We study the transition towards the final state (a) αf = 2379 (beta cell type) and (b) αf = 3437  (alpha cell type). We generated 512 bridge trajectories in each case. The state coordinates are the first two components of a UMAP analysis.
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Reposted by David Yllanes
David Yllanes @davidyllanes.bsky.social · 30/12/2024
Lo más jugado por mí en 2024 (en tiempo total, en número de partidas el primero sería el «Ivanhoe», con 12). Creo que hay una buena mezcla de clásicos y novedades, así como una gran varianza en longitud y complejidad. He compartido partidas con 53 jugadores y probado 42 juegos.
Mis 16 juegos con mayor tiempo total de juego en 2024:

1) OCS Hungarian Rhapsody (MMP), 63 h.
2) Advanced Squad Leader (MMP), 35 h.
3) OCS Tunisia II (MMP), 26 h.
4) OCS Sicily II (MMP), 25 h.
5) Downfall (GMT), 22 h.
6) Arcs (Leder Games), 19 h.
7) BCS Arracourt (MMP), 18 h.
8) GTS Strike-Counterstrike (MMP), 16 h.
9) Europe in Turmoil (Compass), 15 h.
10) Pursuit of Glory (GMT), 14 h.
11) BCS Brazen Chariots (MMP), 10 h.
12) La guerra del anillo (Devir), 9 h.
13) Star Wars Deckbuilding Game (FFG), 9 h.
14) John Company (Wehrlegig), 8 h.
15) Arcs: The Blighted Reach (Leder Games), 8 h.
16) Twilight Imperium (FFG), 8 h.
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David Yllanes @davidyllanes.bsky.social · 30/12/2024
Lo más jugado por mí en 2024 (en tiempo total, en número de partidas el primero sería el «Ivanhoe», con 12). Creo que hay una buena mezcla de clásicos y novedades, así como una gran varianza en longitud y complejidad. He compartido partidas con 53 jugadores y probado 42 juegos.
Mis 16 juegos con mayor tiempo total de juego en 2024:

1) OCS Hungarian Rhapsody (MMP), 63 h.
2) Advanced Squad Leader (MMP), 35 h.
3) OCS Tunisia II (MMP), 26 h.
4) OCS Sicily II (MMP), 25 h.
5) Downfall (GMT), 22 h.
6) Arcs (Leder Games), 19 h.
7) BCS Arracourt (MMP), 18 h.
8) GTS Strike-Counterstrike (MMP), 16 h.
9) Europe in Turmoil (Compass), 15 h.
10) Pursuit of Glory (GMT), 14 h.
11) BCS Brazen Chariots (MMP), 10 h.
12) La guerra del anillo (Devir), 9 h.
13) Star Wars Deckbuilding Game (FFG), 9 h.
14) John Company (Wehrlegig), 8 h.
15) Arcs: The Blighted Reach (Leder Games), 8 h.
16) Twilight Imperium (FFG), 8 h.
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Reposted by David Yllanes
David Yllanes @davidyllanes.bsky.social · 12/12/2024
Spin glasses are the paradigmatic complex systems, but there had been a wide gap between theory and experiment (in time scales and in the accessible observables). This disconnect has now been bridged, quantitatively. We have marked this progress by writing a joint experimental-theoretical review.
The study of spin-glass dynamics, long considered the paradigmatic complex system, has reached important milestones. The availability of high-quality single crystals has allowed the experimental measurement of spin-glass coherence lengths of almost macroscopic dimensions, while the advent of special-purpose massive computers enables dynamical simulations that approach experimental time and length scales. This review provides an account of the quantitative convergence of these two avenues of research, with precise experimental measurements of the expected scaling laws and numerical reproduction of classic experimental results, such as memory and rejuvenation. The article opens with a brief review of the defining spin-glass properties, randomness and frustration, and their experimental consequences. These apparently simple characteristics are shown to generate rich and complex physics. Models are introduced that enable quantitative descriptions. After a summary of the main numerical results in equilibrium, paying particular attention to the concept of temperature chaos, this review examines off-equilibrium dynamics in the absence of a magnetic field and shows how it can be related to equilibrium structures through the fluctuation-dissipation relations. The nonlinear response at a given temperature is then developed, including experiments and scaling in the vicinity of the transition temperature Tg. The consequences of temperature change -- including temperature chaos, rejuvenation, and memory -- are reviewed. The interpretation of these phenomena requires identifying several length scales relevant to dynamics, which, in turn, generate new insights. Finally, issues for future investigations are introduced, including what is to be nailed down theoretically, why the Ising Edwards-Anderson model is so successful at modeling spin-glass dynamics, and experiments yet to be undertaken.Table of contents of the review.
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David Yllanes @davidyllanes.bsky.social · 12/12/2024
Spin glasses are the paradigmatic complex systems, but there had been a wide gap between theory and experiment (in time scales and in the accessible observables). This disconnect has now been bridged, quantitatively. We have marked this progress by writing a joint experimental-theoretical review.
The study of spin-glass dynamics, long considered the paradigmatic complex system, has reached important milestones. The availability of high-quality single crystals has allowed the experimental measurement of spin-glass coherence lengths of almost macroscopic dimensions, while the advent of special-purpose massive computers enables dynamical simulations that approach experimental time and length scales. This review provides an account of the quantitative convergence of these two avenues of research, with precise experimental measurements of the expected scaling laws and numerical reproduction of classic experimental results, such as memory and rejuvenation. The article opens with a brief review of the defining spin-glass properties, randomness and frustration, and their experimental consequences. These apparently simple characteristics are shown to generate rich and complex physics. Models are introduced that enable quantitative descriptions. After a summary of the main numerical results in equilibrium, paying particular attention to the concept of temperature chaos, this review examines off-equilibrium dynamics in the absence of a magnetic field and shows how it can be related to equilibrium structures through the fluctuation-dissipation relations. The nonlinear response at a given temperature is then developed, including experiments and scaling in the vicinity of the transition temperature Tg. The consequences of temperature change -- including temperature chaos, rejuvenation, and memory -- are reviewed. The interpretation of these phenomena requires identifying several length scales relevant to dynamics, which, in turn, generate new insights. Finally, issues for future investigations are introduced, including what is to be nailed down theoretically, why the Ising Edwards-Anderson model is so successful at modeling spin-glass dynamics, and experiments yet to be undertaken.Table of contents of the review.
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David Yllanes @davidyllanes.bsky.social · 09/12/2024
El plato fuerte del puente, «Palestrina» en la Wiener Staatsoper. Mucha expectación por un título tan difícil de ver. Dirigida magistralmente (y con perceptible entusiasmo) por un Thielemann aún en muletas. Muy convincente Michael Spyres en el papel protagonista. El tercer acto ha sido bellísimo.
Thielemann se apoya en sus muletas mientras saluda al público y a la orquesta.Programa de mano de «Palestrina» en la Wiener Staatsoper. Producción de Wernicke.Saludos finales en «Palestrina».
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David Yllanes @davidyllanes.bsky.social · 07/12/2024
Continúa el puente lírico. Hoy, «Der Prozess» de Gottfried von Einem. No la conocía, pero me había gustado mucho «Dantons Tod», del mismo compositor, en una anterior escapada vienesa y tenía expectación. Interesante adaptación de la novela de Kafka y buena producción del Theater an der Wien.
Programa de mano de «Der Prozess» de Gottfried von Einem en el Theater an der Wien. Producción de Stefan Herheim en colaboración con el director musical Walter Kobéra. Anne-Fleur Werner invita al director Walter Kobéra a salir a saludar.Vista general del elenco saludando al público en la Kammeroper de Viena.La pareja protagonista. Ambos firman exitosas interpretaciones.
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David Yllanes @davidyllanes.bsky.social · 07/12/2024
Abrimos este puente con «The Pirates of Penzance» en la English National Opera. Muy divertida reposición de la producción de Mike Leigh. James Creswell hace un buen trabajo como el sargento de policía.
Interior del London Coliseum antes de la función.Programa de mano de la función.Saludos generales. Se aprecia de fondo el gag visual final: una enorme imagen de la reina Victoria que aparece cuando la policía apela al espíritu patriótico (y monárquico) de los piratas, que resultan ser todos miembros de la nobleza.Plano más corto de los saludos. En el centro, el sargento de policía de James Creswell.
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David Yllanes @davidyllanes.bsky.social · 25/05/2024
Gran triunfo de Lise Davidsen como Salomé en la Opéra de Paris. Vocalmente, lo mejor que le he visto con diferencia. Te caes de la butaca cuando canta «Gib' mir den Kopf den Jochaanan».
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David Yllanes @davidyllanes.bsky.social · 09/01/2024
Our paper on vibrations in strained nanoribbons is now out as an editor's suggestion in Phys. Rev. Materials. These ribbons exhibit unusual scale- and temperature-dependent dynamics that could be exploited in the development of graphene-based actuators. journals.aps.org/prmaterials/...
Illustration of the different phases of a doubly clamped nanoribbon (relaxed, stretched, buckled) and of the double-well potential (up and down state) in the buckled phase.Crystalline sheets (e.g., graphene and transition metal dichalcogenides) liberated from a substrate are a paradigm for materials at criticality, because flexural phonons can fluctuate into the third dimension. Although studies of static critical behaviors (e.g., the scale-dependent elastic constants) are plentiful, investigations of dynamics remain limited. Here, we use molecular dynamics to study the time dependence of the midpoint (the height center of mass) of doubly clamped nanoribbons, as prototypical graphene resonators, under a wide range of temperature and strain conditions. By treating the ribbon midpoint as a Brownian particle confined to a nonlinear potential (which assumes a double-well shape beyond the buckling transition), we formulate an effective theory describing the ribbon's transition rate across the two wells and its oscillations inside a given well.
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David Yllanes @davidyllanes.bsky.social · 15/12/2023
Our latest preprint, led by G. Le Treut, is up on the arXiv. We present a method to generate Markov-chain trajectories constrained to an initial and a final state (Markov bridges), which we apply to scRNA data from pancreatic cells to study cell-differentiation pathways arxiv.org/abs/2312.08605
We present a method to sample Markov-chain trajectories constrained to both the initial and final conditions, which we term Markov bridges. The trajectories are conditioned to end in a specific state at a given time. We derive the master equation for Markov bridges, which exhibits the original transition rates scaled by a time-dependent factor. Trajectories can then be generated using a refined version of the Gillespie algorithm. We illustrate the benefits of our method by sampling trajectories in the Müller-Brown potential. This allows us to generate transition paths which would otherwise be obtained at a high computational cost with standard Kinetic Monte Carlo methods because commitment to a transition path is essentially a rare event. We then apply our method to a single-cell RNA sequencing dataset from mouse pancreatic cells to investigate the cell differentiation pathways of endocrine-cell precursors.Markov bridges for a pancreas dataset.
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