BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Two-Point Correlation in Dyson Gases Out-of-Equilibrum DTSTART;VALUE=DATE-TIME:20260417T163000Z DTEND;VALUE=DATE-TIME:20260417T165000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-343@fisindico.uniandes.edu.co DESCRIPTION:Speakers: John Fredy Mateus Rubio (Universidad de los Andes)\n We study the dynamics of a Log-Coulomb gas consisting of N charged particl es confined to a unitary circle and coupled to a thermal bath characterize d by a dimensionless effective parameter $\\beta = q_0^2/(k_BT)$ with $q_0 $ the charge per particle\, $T$ the bath temperature\, and $k_B$ the Boltz mann’s constant. The use of a circular domain eliminates boundary effect s and ensures exact rotational invariance\, leading to an uniform equilibr ium density without external confinement. This geometry isolates universal collective properties and greatly simplifies both static and dynamical an alyses of logarithmic Coulomb gases particularly\, for $\\beta = 2$\, the system can be treated as a free-fermion model\, for which we can obtain an analytical expression for the two-point correlation function in the simpl est case $N = 2$\, and then extend our analysis to $N > 2$ both numericall y and analytically. By varying $\\beta$\, we show that a logarithmic time- law scaling governs the time evolution of this process\, and we verify the validity of the probability distribution of spacings between consecutive particles (levels)\, called Wigner’s surmise\, for $\\beta \\geq 1$ by c omparison with the corresponding Gaussian ensembles for times larger than the relaxation time\, $\\tau \\geq \\tau_{\\text{Eq}}$\, i.e.\, once the s ystem has reached thermal equilibrium.\n\nhttps://fisindico.uniandes.edu.c o/event/23/contributions/343/ LOCATION: URL:https://fisindico.uniandes.edu.co/event/23/contributions/343/ END:VEVENT BEGIN:VEVENT SUMMARY:Field-theoretic Formulation of Ion Correlations with Explicit Hard -Core Size in Aqueous and Non-Aqueous Electrolytes DTSTART;VALUE=DATE-TIME:20260417T161000Z DTEND;VALUE=DATE-TIME:20260417T163000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-331@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Sahin Buyukdagli (Associate Professor\, Bilkent Univ ersity)\nThe accurate formulation of ion correlations in charged solutions is a critical task for the control of various biological and industrial p rocesses ranging from ion transport through cells to water purification pr ocedures. The theoretical tools enabling the comprehension of these system s is based on the Debye-Hückel (DH) theory suffering from major limitatio ns [1]. Namely\, the validity of the DH formalism neglecting the ionic har d-core (HC) size and including exclusively electrostatic weak-coupling-lev el ion correlations is limited to the characterization of monovalent salts at dilute concentrations.\n\nIn this talk\, I will present an ion size-au gmented self-consistent DH (SCDH) theory of bulk electrolytes exploiting t he asymmetric incorporation of the short- and long-range ion interactions via their virial and cumulant-level treatment\, respectively [2\,3]. The u nderlying variational splitting of the distinct interaction ranges enables the accurate prediction of ionic activity coefficients\,\ninternal energi es\, osmotic pressures\, and radial distribution functions of aqueous and non-aqueous electrolytes up to molar salt concentrations. \n\n[1] P. Debye and E. Hückel\, "The theory of electrolytes. I. Lowering of freezing poi nt and related phenomena"\, Zur Theorie der Elektrolyte. Phys. Z. 24\, 185 (1923).\n[2] S. Buyukdagli\, "Self-consistent electrostatic formalism of bulk electrolytes based on the asymmetric treatment of the short- and long -range ion interactions"\, Soft Matter 20\, 9104 (2024).\n[3] S. Buyukdagl i\, "Unified theory of equilibrium thermodynamics and ion association in a queous and non-aqueous electrolytes with explicit hard-core size"\, J. Che m. Theory Comput. 22\, 831 (2026).\n\nhttps://fisindico.uniandes.edu.co/ev ent/23/contributions/331/ LOCATION: URL:https://fisindico.uniandes.edu.co/event/23/contributions/331/ END:VEVENT BEGIN:VEVENT SUMMARY:Criticality and non-reciprocity of catastrophic phase inversion in emulsions DTSTART;VALUE=DATE-TIME:20260417T155000Z DTEND;VALUE=DATE-TIME:20260417T161000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-326@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Andrea Scagliarini (Institute for Applied Mathematic s (IAC)\, National Research Council (CNR))\nThe production of concentrated emulsions involves high-shear flows and it is well known that at a critic al volume fraction the emulsion loses stability\, undergoing an extremely rapid process where the continuous and dispersed phases in the emulsion ex change roles. This process\, called catastrophic phase inversion\, which r esembles in several respects a dynamical phase transition\, has remained w idely elusive from an experimental and theoretical point of view. We prese nt state-of-the-art experimental and numerical data to support a dynamical -system framework capable of precisely highlighting the dynamics occurring in the system as it approaches the catastrophic phase inversion. The stud y clearly highlights that at high volume fractions\, dynamical changes in the emulsion morphology\, due to coalescence and breakup of droplets\, pla y a critical role in determining the emulsion rheology and stability. Addi tionally\, we show that at approaching the critical volume fraction\, the dynamics can be simplified as being controlled by the dynamics of a correl ation length represented\, in our systems\, by the size of the largest dro plet. This dynamics shares a close connection with non-reciprocal phase tr ansition where two different physical mechanisms\, coalescence and breakup s\, can get out of balance leading to large non-symmetric periodic excursi ons in phase space. We clarify the phenomenology observed and quantitative ly explain the essential aspect of the highly complex dynamics of stabiliz ed emulsions undergoing catastrophic phase inversion.\n\nhttps://fisindico .uniandes.edu.co/event/23/contributions/326/ LOCATION: URL:https://fisindico.uniandes.edu.co/event/23/contributions/326/ END:VEVENT BEGIN:VEVENT SUMMARY:Feedback control and the Second Law of thermodynamics in a ratchet physical system DTSTART;VALUE=DATE-TIME:20260416T215000Z DTEND;VALUE=DATE-TIME:20260416T221000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-346@fisindico.uniandes.edu.co DESCRIPTION:Speakers: David Calderón Gómez (Universidad de los Andes)\nW e simulate a realization of Maxwell’s demon based on the experimental se tup developed in \\textit{Bayesian Information Engine that Optimally Explo its Noisy Measurements}\, in which a heavy bead\, immersed in water at roo m temperature\, is trapped by an optical tweezer and lifted through rapid feedback control without net work expenditure. This system functions as an information engine\, harnessing favorable thermal fluctuations to increas e the bead’s gravitational potential energy while keeping the trap’s p otential energy unchanged. Our simulations successfully reproduce key expe rimental findings regarding the engine’s performance across a range of n oisy measurements and verify the Generalized Jarzynski Inequality. In cont rast to previous works that employ a Langevin dynamics approach\, we imple ment a molecular dynamics algorithm to model the system. Our results confi rm that the Generalized Jarzynski Inequality holds for all tested cases\, by a significant margin. This study contributes to the theoretical underst anding of the thermodynamics of mesoscopic systems under feedback control and further reinforces the fundamental connection between information and thermodynamics.\n\nhttps://fisindico.uniandes.edu.co/event/23/contribution s/346/ LOCATION:Universidad de los Andes URL:https://fisindico.uniandes.edu.co/event/23/contributions/346/ END:VEVENT BEGIN:VEVENT SUMMARY:Temporal fluctuation scaling and thermostatistical study of the pe r capita gross domestic products of 105 countries of the world during the period 1960-2023 DTSTART;VALUE=DATE-TIME:20260416T201000Z DTEND;VALUE=DATE-TIME:20260416T203000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-339@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Alejandro Riascos Ochoa (Universidad Nacional de Col ombia)\nWe perform an econophysics study of the gross domestic product per capita (GDPP) data from $N=105$ countries worldwide\, which have annual r ecords in the World Bank database for every year between 1960 and 2023.\nS tarting from the time series of annual values of the average GDPP per coun try and the variance of the GDPP for the period 1960-2023\, we find that t he variance presents a power law relationship with respect to the average\ , that is\, the existence of the scaling of the temporal fluctuation in th is economic system is verified.\nSubsequently\, after verifying that there is also scaling of the time fluctuation for 15-year observation windows\, we studied the annual evolution of the values of the proportionality cons tant and the exponent of the scaling of the time fluctuation during the pe riod 1974-2023\, observing the existence of anticorrelated cycles for thes e two quantities.\nFinally\, defining the economic temperature (Te) as the first absolute moment of the 105 GDPP values with respect to the average GDPP per country\, the economic entropy (Se) as the average Shannon entrop y per country multiplied by $N$\, and the economic chemical potential (Pe) by establishing an analogy with the first law of thermodynamics\, we stud y the temporal evolution of the macroscopic variables Te\, Se\, and Pe ove r the period 1960–2023.\nWe find that\, in terms of these macroscopic va riables\, it is possible to identify historical periods in which different economic factors led to growth or decline dynamics in the annual values o f both the average GDPP per country and the variance of GDPP.\n\nhttps://f isindico.uniandes.edu.co/event/23/contributions/339/ LOCATION:Universidad de los Andes ML-513 URL:https://fisindico.uniandes.edu.co/event/23/contributions/339/ END:VEVENT BEGIN:VEVENT SUMMARY:Spin Glass Dynamics on Complex Hardware Topologies: A Bond-Correla ted Percolation Approach DTSTART;VALUE=DATE-TIME:20260416T163000Z DTEND;VALUE=DATE-TIME:20260416T165000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-327@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Viviana Gómez Ramírez (Universidad de los Andes)\n Understanding how frustration and disorder shape relaxation in complex sys tems is a central challenge in statistical physics and directly relevant t o quantum annealing. Spin-glass models provide a natural setting to addres s this problem\, as their energy landscapes are governed by competing inte ractions and constrained network topologies. In this talk\, I explore the non-exponential relaxation dynamics of spin glasses defined on hardware-re levant graphs such as Chimera\, Pegasus and Zephyr. These architectures im pose finite connectivity and embedding constraints that strongly influence how correlations propagate and how metastable states are organized. Using the Fortuin–Kasteleyn–Coniglio–Klein (FKCK) cluster framework\, I s how that even in the absence of a conventional finite-temperature spin-gla ss transition\, frustration and disorder generate multiple dynamical time scales. The emergence and fragmentation of large-scale clusters provide a geometric interpretation of slow relaxation and reveal how topology contro ls the onset of collective dynamics. This perspective offers a physically transparent way to characterize energy landscapes on realistic annealing h ardware and provides quantitative insight into how graph connectivity and frustration jointly determine the performance and limitations of quantum a nnealing architectures.\n\nhttps://fisindico.uniandes.edu.co/event/23/cont ributions/327/ LOCATION:Universidad de los Andes ML-513 URL:https://fisindico.uniandes.edu.co/event/23/contributions/327/ END:VEVENT BEGIN:VEVENT SUMMARY:Exploration mechanisms intrinsic to semantic networks and the nuan ced appraisal of lexical repetition occurrences DTSTART;VALUE=DATE-TIME:20260413T220000Z DTEND;VALUE=DATE-TIME:20260413T222000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-338@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Gustavo Espinosa Otalora ()\nSemantic memory is resp onsible for storing knowledge of concepts or meanings in the long term. Ba sed on the semantic network from the study by Goñi et al. (2011)\, we stu dy the efficiency and performance of the network using the switching rando m walker model for different transition biases between nodes. Diffusion in the network is described by Markov chains\, a process that allows the cal culation of descriptive random variables such as average first-pass time a nd entropy rate. The MFPT and the entropy rate are very useful measures be cause they provide information about how reachable a node is on average fr om any other node\, and the rate at which information can spread through t he network. In addition\, we designed a fluency test simulation model base d on the changing random walker (SRW) where the relationship between short -term memory (STM)\, the number of repetitions and the flexibility of chan ge is analyzed. STM was found to play an important role in verbal fluency performance\, at least as it relates to verbal fluency tests.\n\nhttps://f isindico.uniandes.edu.co/event/23/contributions/338/ LOCATION:Universidad Nacional Ed. 564 URL:https://fisindico.uniandes.edu.co/event/23/contributions/338/ END:VEVENT BEGIN:VEVENT SUMMARY:Thermostatistical study of the opinion formation phenomenon in the DNAW model DTSTART;VALUE=DATE-TIME:20260413T214000Z DTEND;VALUE=DATE-TIME:20260413T220000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-335@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Jefferson Rubiano Forero (Universidad Nacional DE Co lombia)\nThe model proposed by Default\, Neau\, Amblard\, and Weisbuch (DN AW) is relevant in sociophysics for studying the phenomenon of opinion for mation in social systems composed of agents that interact in a binary mann er. Its relevance lies in the fact that\, through the formulation of an op inion exchange rule between pairs of agents whose opinion differences are smaller than a bounded confidence threshold (d)\, and which is expressed i n terms of a convergence parameter (μ)\, it is possible to reproduce coll ective phenomena observed in social systems such as consensus\, fragmentat ion\, and polarization. Within the framework of this model\, by establishi ng an analogy between a system of social agents and an ideal gas of free p articles\, we present a novel thermostatistical study of the opinion forma tion phenomenon based on the definition of the following macroscopic varia bles: social temperature (Ts)\, social entropy (Ss)\, and social chemical potential (Ps). In particular\, we define Ts as the first absolute moment of the opinions of all agents in the system with respect to the average op inion (Op) per agent. Through numerical simulations that systematically ex plore the parameter space (d\, μ)\, we first identify the equilibrium sta te as the state for which Ss stabilizes and estimate the convergence time as the elapsed time required to reach equilibrium. Subsequently\, we study the opinion formation process by analyzing the temporal evolution of the macroscopic variables Op\, Ts\, Ss\, and Ps. In this way\, we observe that d can be interpreted as a measure of social tolerance to interact with di ffering opinions\, while μ quantifies the degree of mutual influence betw een a pair of agents during an interaction.\n\nhttps://fisindico.uniandes. edu.co/event/23/contributions/335/ LOCATION:Universidad Nacional Ed. 564 URL:https://fisindico.uniandes.edu.co/event/23/contributions/335/ END:VEVENT BEGIN:VEVENT SUMMARY:From motifs to Lévy flights: modeling urban mobility in Bogotá ’s public transport system DTSTART;VALUE=DATE-TIME:20260413T212000Z DTEND;VALUE=DATE-TIME:20260413T214000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-324@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Juan Felipe Alayón Martínez (Universidad Nacional de Colombia)\nPaper published in 2026: we study two years of access card v alidation records from Bogotá’s multimodal public transport system\, co mprising over 2.3 billion trips across bus rapid transit\, feeder buses\ , dual-service buses\, and an aerial cable network. From user trajectories constructed exclusively from access records\, we derive motifs that revea l recurrent mobility patterns extending beyond simple two-location visits. This approach enables the construction of an integrated origin–destinat ion (OD) matrix covering 2828 urban zones. Similarity analysis using the J ensen–Shannon divergence confirms the temporal stability of mobility str uctures across semesters\, despite infrastructure changes and fare policy adjustments. From the obtained OD matrices\, we derive transition probabil ities between zones and uncover a robust power-law relationship with geogr aphical distance\, consistent with Lévy flight dynamics. We validate our model using Monte Carlo simulations showing that reproduces both local and long-range displacements\, with similar scaling exponents across time. Th ese findings demonstrate that Bogotá’s public transport mobility can be effectively modeled through Lévy processes\, providing a novel framework for analyzing complex transportation systems based solely on user access records.\n\nhttps://fisindico.uniandes.edu.co/event/23/contributions/324/ LOCATION:Universidad Nacional Ed. 564 URL:https://fisindico.uniandes.edu.co/event/23/contributions/324/ END:VEVENT BEGIN:VEVENT SUMMARY:Fast thermal equilibration using machine learning DTSTART;VALUE=DATE-TIME:20260413T164000Z DTEND;VALUE=DATE-TIME:20260413T170000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-342@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Diego Rengifo (Technical University Berlin )\nFast t hermal equilibration\, also known as a shortcut to adiabaticity\, is an ex ternal control technique employed to expedite operations beyond the system ’s natural timescale. In this talk\, we will introduce a machine learnin g technique\, specifically automatic differentiation\, to identify control protocols that accelerate the equilibration process in stochastic systems modeled by the overdamped Langevin equation.\n\nhttps://fisindico.uniande s.edu.co/event/23/contributions/342/ LOCATION:Universidad Nacional de Colombia Ed. 564 URL:https://fisindico.uniandes.edu.co/event/23/contributions/342/ END:VEVENT BEGIN:VEVENT SUMMARY:Very persistent random walkers reveal transitions in landscape top ology DTSTART;VALUE=DATE-TIME:20260413T162000Z DTEND;VALUE=DATE-TIME:20260413T164000Z DTSTAMP;VALUE=DATE-TIME:20260408T223144Z UID:indico-contribution-92-329@fisindico.uniandes.edu.co DESCRIPTION:Speakers: Jaron Kent-Dobias (ICTP-SAIFR & IFT-UNESP)\nIn large random systems\, certain behaviors are reliably predicted\, like the ener gy density of the ground state. The long-time behavior of many physical an d algorithmic dynamics is likewise predictable\, through DMFT and related approaches. But can these behaviors be connected to static structures of t he problem at hand\, like its energy landscape? Recently\, development of the Overlap Gap Property\, which depends on the existence of a system-span ning component of the energy level set\, suggests that static topological properties can predict the performance of the best algorithms. Here\, I wi ll describe progress towards predicting the performance of the mediocre bu t simple algorithms we usually use. We use the ergodicity of a random walk er to probe whether typical configurations belong to a system-spanning com ponent of the energy level set. Passive random walkers lose ergodicity at a depth associated with the glass transition\, but active random walkers r emain ergodic to greater depth. We argue that in the limit of infinite per sistence time\, the ergodicity-breaking transition coincides with the poin t at which system-spanning components become atypical\, and discuss connec tions with gradient descent dynamics.\n\nhttps://fisindico.uniandes.edu.co /event/23/contributions/329/ LOCATION:Universidad Nacional de Colombia Ed. 564 URL:https://fisindico.uniandes.edu.co/event/23/contributions/329/ END:VEVENT END:VCALENDAR