Physical review. E最新文献_第9页

Evidence of dual energy transfer driven by magnetic reconnection at subion scales. 亚尺度磁重联驱动的双重能量转移证据。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.055207

Raffaello Foldes, Silvio Sergio Cerri, Raffaele Marino, Enrico Camporeale

引用次数: 0

Hyperballistic transport in dense systems of charged particles under ac electric fields. 带电粒子密集系统在交流电场下的超弹道传输。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054137

Daniele Gamba, Bingyu Cui, Alessio Zaccone

{"title":"Hyperballistic transport in dense systems of charged particles under ac electric fields.","authors":"Daniele Gamba, Bingyu Cui, Alessio Zaccone","doi":"10.1103/PhysRevE.110.054137","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054137","url":null,"abstract":"The Langevin equation is ubiquitously employed to numerically simulate plasmas, colloids, and electrolytes. However, the usual assumption of white noise becomes untenable when the system is subject to an external ac electric field. This is because the charged particles in the system, which provide the thermal bath for the particle transport, become themselves responsive to the ac field and the thermal noise is field dependent and non-Markovian. We theoretically study the particle diffusivity in a Langevin transport model for a tagged charged particle immersed in a dense system of charged particles (plus also, possibly, other neutral particles) that act as the thermal bath, under an external ac electric field. This is done by properly accounting for the effects of the ac field on the thermal bath statistics. We analytically derive the time-dependent generalized diffusivity D(t) for different initial conditions. The generalized diffusivity exhibits damped oscillatory-like behavior with initial very large peaks, where the generalized diffusion coefficient is enhanced by orders of magnitude with respect to the infinite-time steady-state value. The latter coincides with the Stokes-Einstein diffusivity in the absence of an external field. For initial conditions where the external field is already on at t=0 and the system is thermalized under dc conditions for t≤0, the short-time behavior is hyperballistic, MSD∼t^{4} (where MSD is the mean-squared displacement), leading to giant enhancement of the particle transport. Finally, the theory elucidates the role of medium polarization on the local Lorentz field, and allows for estimates of the effective electric charge due to polarization by the surrounding charges.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054137"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Symmetry breaking and gait transition induced by hydrodynamic sensory feedback in an anguilliform swimming robot. 鳗形游泳机器人的水动力感觉反馈引起的对称破坏和步态转变。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.055104

Johann Herault, Laura Paez, Kamilo Melo, Robin Thandiackal, Vincent Lebastard, Frédéric Boyer, Auke Ijspeert

{"title":"Symmetry breaking and gait transition induced by hydrodynamic sensory feedback in an anguilliform swimming robot.","authors":"Johann Herault, Laura Paez, Kamilo Melo, Robin Thandiackal, Vincent Lebastard, Frédéric Boyer, Auke Ijspeert","doi":"10.1103/PhysRevE.110.055104","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.055104","url":null,"abstract":"The goal of this article is to identify and understand the fundamental role of spatial symmetries in the emergence of undulatory swimming using an anguilliform robot. Here, the local torque at the joints of the robot is controlled by a chain of oscillators forming a central pattern generator (CPG). By implementing a symmetric CPG with respect to the transverse plane, motor activation waves are inhibited, preventing the emergence of undulatory swimming and resulting in an oscillatory gait. We show experimentally that the swimmer can recover from the traveling wave inhibition by using distributed fluid force feedback to modulate the phase dynamics of each oscillator. This transition from oscillatory to undulating swimming is characterized by a symmetry breaking in the CPG and the body dynamics. By studying the stability of the oscillator chain, we show that the sensory feedback produces a frequency detuning gradient along the CPG chain while preserving its stability. To explain the origin of the instability, we introduce a toy model where the couplings between the dynamics of the oscillators and the body deformation reinforce the symmetry breaking.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-2","pages":"055104"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of smectic polymers on cholesteric liquid crystals. 近晶聚合物对胆甾液晶的影响。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054703

Zhaofei Zheng, Francesca Serra

{"title":"Effect of smectic polymers on cholesteric liquid crystals.","authors":"Zhaofei Zheng, Francesca Serra","doi":"10.1103/PhysRevE.110.054703","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054703","url":null,"abstract":"Composite materials made of polymers and liquid crystals have been widely employed in smart windows, optical filters, and bistable displays. However, it is often difficult to decipher the role of the polymer network architecture on the alignment and the texture of liquid crystals. In this study, we use a simple model system where a small amount of polymerizable liquid crystalline monomer is mixed in a liquid crystal that exhibits both a smectic phase and a cholesteric phase with a large helical pitch. By cross-linking the monomer in the smectic phase, the liquid crystal textures become significantly altered. The existence of a polymer network not only creates resistance to form a helix and therefore hinders the formation of cholesteric fingerprints but also modifies the structure of the cholesteric texture. We investigate the effects of changing the concentration of chiral dopant and monomer on the formation and growth of the cholesteric fingerprint texture during the phase transition and on the width of the fingerprints. We find that, within a certain parameter range, the cholesteric fingerprints do not depend on the concentration of the chiral dopant. We explain this phenomenon by hypothesizing that the polymer network acts as a bulk alignment field.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054703"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of clustering heterogeneity on the spectral density of sparse networks. 聚类异质性对稀疏网络谱密度的影响。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054307

Tuan Minh Pham, Thomas Peron, Fernando L Metz

引用次数: 0

Exact cluster dynamics of indirect reciprocity in complete graphs. 完全图中间接互易的精确聚类动力学。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.L052301

Minwoo Bae, Takashi Shimada, Seung Ki Baek

{"title":"Exact cluster dynamics of indirect reciprocity in complete graphs.","authors":"Minwoo Bae, Takashi Shimada, Seung Ki Baek","doi":"10.1103/PhysRevE.110.L052301","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.L052301","url":null,"abstract":"Heider's balance theory emphasizes cognitive consistency in assessing others, as expressed by the phrase \"The enemy of my enemy is my friend.\" At the same time, the theory of indirect reciprocity provides us with a dynamical framework to study how to assess others based on their actions as well as how to act toward them based on the assessments. Well known are the \"leading eight\" from L1 to L8, the eight norms for assessment and action to foster cooperation in social dilemmas while resisting the invasion of mutant norms prescribing alternative actions. In this work, we begin by showing that balance is equivalent to stationarity of dynamics only for L4 and L6 (stern judging) among the leading eight. Stern judging reflects an intuitive idea that good merits reward, whereas evil warrants punishment. By analyzing the dynamics of stern judging in complete graphs, we prove that this norm almost always segregates the graph into two mutually hostile groups as the graph size grows. We then compare L4 with stern judging: The only difference of L4 is that a good player's cooperative action toward a bad one is regarded as good. This subtle difference transforms large populations governed by L4 to a \"paradise\" where cooperation prevails and positive assessments abound. Our study thus helps us understand the relationship between individual norms and their emergent consequences at a population level, shedding light on the nuanced interplay between cognitive consistency and segregation dynamics.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5","pages":"L052301"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Competition between merging and bifurcation in the generalized Rayleigh-Taylor instability. 广义瑞利-泰勒不稳定性中合并与分岔之间的竞争。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.055201

Q Cauvet, B Bernecker, B Canaud

引用次数: 0

Explicit solutions of the Bass and susceptible-infected models on hypernetworks. 超网络上Bass和易受感染模型的显式解。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054306

Gadi Fibich, Juan G Restrepo, Guy Rothmann

引用次数: 0

Active motion can be beneficial for target search with resetting in a thermal environment. 主动运动可以有利于目标搜索与重置在热环境。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054124

P S Pal, Jong-Min Park, Arnab Pal, Hyunggyu Park, Jae Sung Lee

{"title":"Active motion can be beneficial for target search with resetting in a thermal environment.","authors":"P S Pal, Jong-Min Park, Arnab Pal, Hyunggyu Park, Jae Sung Lee","doi":"10.1103/PhysRevE.110.054124","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054124","url":null,"abstract":"Stochastic resetting has recently emerged as an efficient target-searching strategy in various physical and biological systems. The efficiency of this strategy depends on the type of environmental noise, whether it is thermal or telegraphic (active). While the impact of each noise type on a search process has been investigated separately, their combined effects have not been explored. In this work, we explore the effects of stochastic resetting on an active system, namely a self-propelled run-and-tumble particle immersed in a thermal bath. In particular, we assume that the position of the particle is reset at a fixed rate with or without reversing the direction of self-propelled velocity. Using standard renewal techniques, we compute the mean search time of this active particle to a fixed target and investigate the interplay between active and thermal fluctuations. We find that the active search can outperform the Brownian search when the magnitude and flipping rate of self-propelled velocity are large and the strength of environmental noise is small. Notably, we find that the presence of thermal noise in the environment helps reduce the mean first passage time of the run-and-tumble particle compared to the absence of thermal noise. Finally, we observe that reversing the direction of self-propelled velocity while resetting can also reduce the overall search time.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054124"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interaction of complex particles: A framework for the rapid and accurate approximation of pair potentials using neural networks. 复杂粒子的相互作用：利用神经网络快速准确地逼近对势的框架。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.055305

Gusten Isfeldt, Fredrik Lundell, Jakob Wohlert

{"title":"Interaction of complex particles: A framework for the rapid and accurate approximation of pair potentials using neural networks.","authors":"Gusten Isfeldt, Fredrik Lundell, Jakob Wohlert","doi":"10.1103/PhysRevE.110.055305","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.055305","url":null,"abstract":"Motivated by the limitations of conventional coarse-grained molecular dynamics for simulation of large systems of nanoparticles and the challenges in efficiently representing general pair potentials for rigid bodies, we present a method for approximating general rigid body pair potentials based on a specialized type of deep neural network that maintains essential properties, such as conservation of energy and invariance to the chosen origins of the particles. The network uses a specialized geometric abstraction layer to convert the relative coordinates of the rigid bodies to input more suitable to a conventional artificial neural network, which is trained together with the specialized layer. This results in geometric representations of the particles optimized for the specific potential. The network can be trained directly on scalar values to fit a model without explicit gradient and then used to efficiently evaluate the force and torque on the particles resulting from the potential. The concept is demonstrated with an atomistic interaction model for carbon nanotubes and the resulting model is compared with a common type of coarse-grained model optimized for the same potential, with even very small networks comparing favourably and larger networks achieving up to two orders of magnitude lower cost. The sensitivity to noise in the training data is investigated and the model is found to strongly reject noise up to 12.5% given a dataset of 10^{7} samples. The performance of a proof-of-concept implementation is demonstrated on a variety of hardware, showing the models viability for large-scale simulations. Furthermore, generalization to soft bodies and potentials for polydisperse systems are discussed.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-2","pages":"055305"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0