This research investigates a class of one-dimensional theories characterized by a distinctly defined infinite interaction range. We propose that such theories emerge naturally through a mesoscopic feedback mechanism. In this proof-of-concept study, we examine Ising-type models and a model with continuous $O$(3) symmetry, and demonstrate that the natural emergence of phase transitions, criticality, spontaneous symmetry breaking and previously unidentified universality classes is evident. The framework introduced here holds particular relevance for monolayer spintronics research, where the ultimate goal is to achieve a strong ferromagnetic order at room temperature.

To simulate indistinguishable particles, recent studies of path-integral molecular dynamics formulated their partition function $Z$ as a recurrence relation involving a variable $\xi$, with $\xi =1$(−1) for bosons (fermions). Inspired by Lee-Yang phase transition theory, we extend $\xi$ into the complex plane and reformulate $Z$ as a polynomial in $\xi$. By analyzing the distribution of the partition function zeros, we gain insights into the analytical properties of indistinguishable particles, particularly regarding the fermion sign problem (FSP). We found that at 0 K, the partition function zeros for $N$ particles are located at $\xi =-1, -1/2, -1/3, ..., -1/(N-1)$. This distribution disrupts the analytic continuation of thermodynamic quantities, expressed as functions of $\xi$ and typically performed along $\xi =1\to -1$, whenever the paths intersect these zeros. Moreover, we highlight the zero at $\xi =-1$, which induces an extra term in the free energy of the fermionic systems compared to ones at other $\xi =e^{i\theta }$ values. If a path connects this zero to a bosonic system with identical potential energies, it brings a transition resembling a phase transition. These findings provide a fresh perspective on the successes and challenges of emerging FSP studies based on analytic continuation techniques.

Quantum many-body scars have received much recent attention for being both intriguing nonergodic states in otherwise quantum chaotic systems and promising candidates to encode quantum information efficiently. So far, these studies have mostly been restricted to Hermitian systems. Here, we study many-body scars in many-body quantum chaotic systems coupled to a Markovian bath, which we term Lindblad many-body scars. They are defined as simultaneous eigenvectors of the Hamiltonian and dissipative parts of the vectorized Liouvillian. Importantly, because their eigenvalues are purely real, they are not related to revivals. The number and nature of the scars depend on both the symmetry of the Hamiltonian and the choice of jump operators. For a dissipative four-body Sachdev-Ye-Kitaev (SYK) model with $N$ fermions, either Majorana or complex, we construct analytically some of these Lindblad scars while others could only be obtained numerically. As an example of the former, we identify $N/2+1$ scars for complex fermions due to the $U\left(1\right)$ symmetry of the model and two scars for Majorana fermions as a consequence of the parity symmetry. Similar results are obtained for a dissipative XXZ spin chain. We also characterize the physical properties of Lindblad scars. First, the operator size is independent of the disorder realization and has a vanishing variance. By contrast, the operator size for nonscarred states, believed to be quantum chaotic, is well described by a distribution centered around a specific size and a finite variance, which could be relevant for a precise definition of the eigenstate thermalization hypothesis in dissipative quantum chaos. Moreover, the entanglement entropy of these scars has distinct features such as a strong dependence on the partition choice and, in certain cases, a large entanglement.

In this article, we present a study of the macroscopic and microscopic dynamics of the two-dimensional cellular automaton Q2R-Potts, which is an extension of the Q2R model. This extension takes into account interactions between more than two states. Specifically, we simulated its dynamics for three states $(q=3)$. We observed that the system undergoes a second-order phase transition starting from a critical energy value $E_c/N$, which is equivalent to the critical value of the Potts model. Motivated by the observation of microscopic dynamics, we provide an exact characterization and quantification of cluster formation through subgraph connections. This allowed us to determine the critical cluster size that occurs during the phase transition, the development of a scale-free distribution, and the domain of states that form a chessboardlike structure.

We study the stability of steady-state solutions of the Wave Kinetic Equations for acoustic waves. Combining theoretical analysis and numerical simulations, we characterise the time evolution of small isotropic perturbations for both two- and three-dimensional equilibrium Rayleigh-Jeans and nonequilibrium Kolmogorov-Zakharov solutions. In particular, we show that the stability of these solutions is ensured by different mechanisms.

The influence of conical wire array geometry on the formation and dynamics of pulsed-power driven plasma jets is investigated. In the experiments, the jet becomes isolated from the inflows as it passes through an aperture, allowing the study of its intrinsic evolution for different conical angles. Our results show that, regardless of the array opening angle, the jets are supersonic, highly collisional, and exhibit an exponential axial density decay with a characteristic scale length of $L_n\approx 3\mathrm{mm}$, significantly shorter than the overall length of the jet. In contrast, axial velocity systematically increases with larger array opening angles. The near invariance of the density profile is attributed to a compensating mechanism between geometric divergence and axial acceleration, consistent with an asymptotically steady flow regime. Additionally, temperature measurements reveal ion-electron thermal decoupling near the base of the jet, with equilibration downstream. Analysis of radiative cooling and collisional energy exchange timescales indicates that the plasma evolves in a radiatively stable regime and that the two-temperature profile is fully described by the competition between both methods. These findings provide valuable information into the internal structure and evolution of pulsed-power plasma jets in regimes dominated by geometric shaping and radiative cooling, demonstrating experimental control over flow acceleration and collimation relevant to both laboratory and astrophysical contexts.

We study a one-dimensional lattice model of particles following hard-core exclusion and performing opposing local and nonlocal moves with probability $p$ and $1-p$, respectively. Our model shows the interesting feature that the direction of the particle current can be switched by simply changing the density $\rho$ of particles on the lattice. We study the dependence of current on $p$ as well as $\rho$ and present the separation of positive and negative current regions on a $p-\rho$ plane. Further, we study the effect of disorder on this model by introducing a single site with valvelike dynamics. The site allows only unidirectional, local outward motion with rate $r$. The interplay of the disorder strength $r$, particle density $\rho$, and probability $p$ leads to a rich possibility with four different kinds of shock phases in the steady state. We study the shock densities using Monte Carlo simulations and mean field calculations. While our mean field treatment describes the numerical results quite well qualitatively, we see certain quantitative deviations. We try to understand these deviations using measures of correlation in the system and provide heuristic arguments for the mismatch.

Eco-evolutionary games describe the mutual feedback between strategic actions and environmental conditions. Earlier studies have demonstrated that this interplay can lead to a range of dynamic behaviors, including persistent oscillations and heteroclinic cycles, the latter representing an oscillating tragedy of commons. We extend the canonical replicator-environment coupled model by incorporating a fixed fraction of zealous cooperators who adhere to cooperation independently of payoffs. The resulting system admits four equilibrium states for the coupled strategy-environment dynamics. We derive stability conditions for each equilibrium and show analytically that the presence of zealots suppresses oscillatory behavior. Increasing the density of zealots induces a sequence of bifurcations leading from an interior coexistence state to partial cooperation in a replete environment and ultimately to full cooperation with a rich environment. Numerical experiments further demonstrate that stronger environmental enhancement amplifies the stabilizing influence of zealots and enlarges the parameter regime supporting replete environmental states. Our results reveal that committed cooperators act as a stabilizing mechanism capable of eliminating the oscillating tragedy of commons in eco-evolutionary dynamics and sustaining long-term cooperative and environmentally favorable outcomes.

We introduce a scheme for contact angle hysteresis in the presence of moving curved solid boundaries for a class of two-phase fluid models, where the interface between fluid phases is diffuse, while the ones involving solid phases are sharp. The scheme essentially reconstructs a ghost-node phase-field profile based on an Allen-Cahn equation along the solid surface. After validating the combined phase-field lattice Boltzmann approach with benchmarks in constant contact angle mode, we systematically investigate the hysteresis behavior with three benchmarks: (1) a cylinder rotating at a fluid-fluid interface, (2) a capillary bridge between two parallel plates that is stretched by separating the plates at a constant velocity, and (3) a cylinder equilibrating in a liquid pool under gravity. In all cases, contact line pinning is reproduced accurately, including the transition between the pinned and depinned states. The force and torque measured on the solid surface agree well with analytical solutions.

Follower activity results in a large variety of conformational and dynamical states in active chains and filaments. These states are formed due to the coupling between chain geometry and the local activity. We study the origin and emergence of such patterns in noiseless, flexible active chains. In the overdamped limit, we observed a range of dynamical steady states for different chain lengths $\left(N\right)$. The steady-state planar trajectories of the center of mass of the chain include circles, periodic waves, and quasiperiodic, bound trajectories resembling spirographic patterns. In addition, out-of-plane initial configuration also leads to the formation of three-dimensional structures, including globular and supercoiled helical structures. For the shortest chain with three segments $(N=3)$, the chain always moves in a circular trajectory. Such circular trajectories are also observed in the limit of large chain lengths $(N\gg 1)$. We analytically study the dynamical patterns in these two limiting cases, which show quantitative and qualitative matches with numerical simulations. Our analytical study also provides an estimate of the limiting $N$ where the large-chain-length behavior is expected. These analyses reveal the existence of such intricately periodic patterns in active chains, arising due to the follower activity.

Nanoparticle-polymer composites offer versatile platforms for engineering tunable soft materials with tailored structural and functional properties. The anionic silica nanoparticles dispersed in polymer solutions exhibit a remarkable reentrant phase behavior, where interparticle interactions evolve from repulsive to attractive and back to repulsive (or less attractive) with increasing polymer concentration. This evolution of interaction is accompanied by a corresponding rise and subsequent fall in the hydrodynamic size and viscosity of the system, reflecting a transition from stable to aggregated state followed by restabilization. We show that the phase boundaries of this behavior can be effectively tuned by adjusting the nanoparticle concentration and/or ionic strength. Increasing nanoparticle concentration shifts the attractive regime to higher polymer concentrations, while elevated ionic strength broadens this regime. Such tuning of phase boundaries enables precise control and targeted attainment of stable or aggregated states in nanoparticle-polymer systems. The systems are examined by dynamic light scattering, viscosity, and small-angle neutron scattering. The results demonstrate that controlled modulation of interparticle interactions (electrostatic repulsion, depletion attraction and stabilization) through nanoparticle, polymer, and salt concentrations offers a powerful strategy for designing responsive nanoparticle–polymer complexes.

In order to investigate locally extractable energy from multipartite entangled pure states, we introduce effective thermodynamics by defining an entanglement-based effective temperature. Based on the effective thermodynamics, we derive an upper bound on extractable energy with feedback control from a subsystem under a local Hamiltonian. The inequality that gives the upper bound corresponds to the second law of information thermodynamics in our effective thermodynamics. In addition, we derive a more general bound that is determined only by an initial state and the local Hamiltonian. This bound gives an explicit relationship between the extractable energy and the entanglement structure of the initial state. Using the entanglement-based effective temperature, we discuss how our energy extraction protocol on pure states is related to ordinary information thermodynamic processes and show the consistency of our results with previous information thermodynamics. We also investigate the tightness of the upper bounds and show that the bounds can be achieved in a simple example.

Many diffusive systems involve correlated random walkers due to a shared environment. Such systems can be modeled as random walks in random environments (RWRE). These models differ from classical diffusion in the behavior of the extremes—the walkers that move the fastest or farthest. In spatial dimension $d=1$, RWRE models have been well studied numerically and analytically and exhibit universal behavior in the Kardar-Parisi-Zhang universality class. Here we study discrete lattice RWRE models in $d=2$. We find that the tail probability exhibits a different universal scaling form, which is nevertheless characterized by the same coefficient, ${\lambda }_{\mathrm{ext}}$, as in the $d=1$ case. We observe a critical scaling regime for fluctuations in the tail probability at positions that scale linearly in time.

Nonequilibrium chiral active systems exhibit diverse collective phenomena arising from the interplay between driving forces and interparticle interactions. We numerically investigate a two-dimensional system of particles with competing long-range repulsion and short-range attraction, driven by nonconservative odd forces. We identify five distinct nonequilibrium phases: a crystalline state with long-range translational and orientational order; a triangular velocity configuration exhibiting velocity-space ordering; a nematic phase featuring orientational alignment without polar order; a bubble phase with vortical flows along void boundaries; and a rotating cluster phase showing dynamic restructuring. The transitions between these phases are systematically controlled by varying the attraction strength and the odd-force intensity, revealing a rich phase diagram. Our results underscore the crucial role of odd forces in steering the structural and dynamical evolution of active matter with competing interactions.

In this article, we examine random disordered arrays of infinitely long cylinders of revolution, all with the same diameter and allowed to overlap. These arrangements can be considered as simple representations of fibrous media, which are widely used in the field of high-performance thermal insulation. In a cylinder of revolution of infinite length, the expression of the cumulative distribution function of internal $i$-random chord lengths $F_i\left(s\right)$ is given in terms of elliptic integrals, and some notable properties are highlighted. It is shown that there is a link between $F_i\left(s\right)$ and the sphere/solid cylinder intersection area. A statistically homogeneous and isotropic arrangement of infinite cylinders is then studied. An algorithm for generating such a medium is reviewed, and the resulting elementary properties are given. Finally, a study in the field of stochastic geometry makes it possible to determine an analytical expression for the autocorrelation function (two-point probability function) inside the solid phase and, more generally, for the number of overlaps probability function. This makes it possible to deduce, in the Laplace domain, an expression for the cumulative distribution function of $i$-random chord lengths $F_i(\mathrm{\Pi },s)$ within the solid phase for any porosity $\mathrm{\Pi }$. The autocorrelation function also allows one to define a representative elementary volume (REV) related to local fluctuations in porosity.

We investigate thermalization of one-dimensional lattices with asymmetric interactions. For the FPUT-$\alpha \beta$ lattices with different boundary conditions, we observe distinct thermalization behaviors. Specifically, we find that the Toda lattice with free boundary conditions exhibits asymptotic integrability, which accounts for these differences. The FPUT-$\alpha \beta$ lattice and the Toda lattice with free boundary conditions should be classified as a perturbed Harmonic lattice. The scaling relationship between the thermalization time and the specified perturbation strength remains consistent with the predictions of the wave turbulence theory. The impact of internal pressure on the scaling relationship is also briefly discussed.

We study the Hegselmann-Krause model of opinion dynamics on sparse, unbiased networks generated via Wilson's algorithm, unveiling how network connectivity and confidence bounds jointly determine collective behavior. By systematically exploring the parameter space spanned by the confidence level $\epsilon$ and the mean degree density $\mu$, we construct comprehensive phase diagrams that classify the emergent steady states into different degrees of fragmentation and consensus. We uncover a nonmonotonic reentrant transition where increased connectivity can paradoxically suppress consensus, and show that full unanimity is unattainable at low connectivity due to structural isolation. Convergence times exhibit two distinct slowdowns: a finite-size, connectivity-dependent resonance near $\epsilon \sim 1/N$, and a critical peak associated with the established fragmentation-to-consensus transition. While the critical confidence threshold ${\epsilon }_c$ stabilizes near 0.2 for large system sizes, finite-size effects and sparse connectivity significantly alter the dynamics and phase boundaries in smaller populations. Our results offer insights into the interplay between network topology and opinion dynamics, and highlight conditions under which increased connectivity may hinder, rather than promote, consensus.

Chromosomal translocations, arising from unresolved double-stranded DNA breaks (DSBs), play a central role in genome instability and evolution. A prevailing hypothesis suggests that the probability of translocation between two chromatin segments depends on both their spatial proximity and the likelihood of DSB formation and rejoining. To test this, we perform Monte Carlo simulations of chromatin model polymers with varying levels of compaction and three-dimensional organization. Our results reveal that translocation probability cannot be fully explained by simple two-segment contact probabilities. Instead, it is strongly modulated by the global polymer compaction, which increases the incidence of multisegment contacts and introduces higher-order contributions. We further demonstrate that translocation probability exhibits a nontrivial functional dependence on both contact probability and DSB probability. We propose an empirical formula to compute translocation probability and provide analytical arguments for simple cases. Together, our findings highlight the critical role of chromatin organization in shaping the landscape of genome rearrangements and provide a framework to quantitatively predict translocation events from underlying polymer features and breakage statistics.