Physical Review E最新文献_第10页

Amoeba Monte Carlo algorithms for random trees with controlled branching activity: Efficient trial move generation and universal dynamics. 具有受控分支活动的随机树的阿米巴蒙特卡洛算法：高效的试验移动生成和通用动力学。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.045312

Pieter H W van der Hoek, Angelo Rosa, Ralf Everaers

引用次数: 0

Isotropic tensor fields in amorphous solids: Correlation functions of displacement and strain tensor fields. 无定形固体中的各向同性张量场：位移和应变张量场的相关函数。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044604

J P Wittmer, J Baschnagel

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Order-disorder behavior in the ferroelectric nematic phase investigated via Raman spectroscopy. 通过拉曼光谱研究铁电向列相的有序-无序行为。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044702

Thomas Raistrick, Richard J Mandle, Zhaopeng Zhang, Peter J Tipping, Helen F Gleeson

{"title":"Order-disorder behavior in the ferroelectric nematic phase investigated via Raman spectroscopy.","authors":"Thomas Raistrick, Richard J Mandle, Zhaopeng Zhang, Peter J Tipping, Helen F Gleeson","doi":"10.1103/PhysRevE.110.044702","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044702","url":null,"abstract":"Polar-ordered fluids are of interest both fundamentally and from an application standpoint. The recently discovered ferroelectric nematic phase is an example of a polar-ordered fluid, and while there has been extensive research interest in these materials, some of the fundamental properties are yet to be fully understood. Here, we report the order parameters of one of the first known materials that exhibit a ferroelectric nematic phase, RM734, determined via Raman spectroscopy. Raman spectroscopy been used extensively to determined order parameters in liquid crystals systems but also to probe ferroelectric behavior in solid ferroelectric systems and is therefore a powerful technique to study the ferroelectric nematic phase. A reduction and subsequent recovery of order parameters (Δ〈P_{2}〉≈0.1, Δ〈P_{4}〉≈0.06) is observed near the onset of the N to N_{F} transition, a feature that is confirmed via complementary birefringence measurements. This dip in order parameters has been attributed to splay fluctuations, which occur at the onset of the N_{F} transition; here we suggest a different explanation. A broadening of the full-width half-maxima (FWHM), of the order of 1 cm^{-1}, of the selected Raman peak is observed near the N to N_{F} phase transition, which we relate to either a change in reorientational dynamics or the onset of polar order. The N_{F} transition is analyzed using standard solid ferroelectric frameworks. An energetic barrier associated with the para- to ferroelectric transition is found to be of the order of 2.5±0.6kJ/mol, which is comparable to solid ferroelectric materials.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044702"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677594","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

Parameter estimation from an Ornstein-Uhlenbeck process with measurement noise. 带有测量噪声的 Ornstein-Uhlenbeck 过程的参数估计。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044112

Simon Carter, Lilianne R Mujica-Parodi, Helmut H Strey

{"title":"Parameter estimation from an Ornstein-Uhlenbeck process with measurement noise.","authors":"Simon Carter, Lilianne R Mujica-Parodi, Helmut H Strey","doi":"10.1103/PhysRevE.110.044112","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044112","url":null,"abstract":"We investigate the impact of noise on parameter fitting for an Ornstein-Uhlenbeck process, focusing on the effects of multiplicative and thermal noise on the accuracy of signal separation. To address these issues, we propose algorithms and methods that can effectively distinguish between thermal and multiplicative noise and improve the precision of parameter estimation for optimal data analysis. Specifically, we explore the impact of both multiplicative and thermal noise on the obfuscation of the actual signal and propose methods to resolve them. First, we present an algorithm that can effectively separate thermal noise with comparable performance to Hamilton Monte Carlo (HMC) methods, but with significantly improved speed. We then analyze multiplicative noise and demonstrate that HMC is insufficient for isolating thermal and multiplicative noise. However, we show that with additional knowledge of the ratio between thermal and multiplicative noise, we can accurately distinguish between the two types of noise when provided with a sufficiently large sampling rate or an amplitude of multiplicative noise that is smaller than the thermal noise. Thus, we demonstrate the mechanism underlying an otherwise counterintuitive phenomenon: when multiplicative noise dominates the noise spectrum, one can successfully estimate the parameters for such systems after adding additional white noise to shift the noise balance.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044112"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677595","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

Image charge effects under metal and dielectric boundary conditions. 金属和介质边界条件下的图像电荷效应

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044129

Tingtao Zhou, Dorian Bruch, Zhen-Gang Wang

引用次数: 0

Escape from a metastable state in non-Markovian population dynamics. 在非马尔可夫种群动力学中逃离可变状态

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044132

Ohad Vilk, Michael Assaf

{"title":"Escape from a metastable state in non-Markovian population dynamics.","authors":"Ohad Vilk, Michael Assaf","doi":"10.1103/PhysRevE.110.044132","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044132","url":null,"abstract":"We study the long-time dynamics in non-Markovian single-population stochastic models, where one or more reactions are modeled as a stochastic process with a fat-tailed nonexponential distribution of waiting times, mimicking long-term memory. We focus on three prototypical examples: genetic switching, population establishment, and population extinction, all with nonexponential production rates. The system is studied in two regimes. In the first, the distribution of waiting times has a finite mean. Here, the system approaches a (quasi)stationary steady state at long times, and we develop a general Wentzel-Kramers-Brillouin approach for these non-Markovian systems. We derive explicit results for the mean population size and mean escape time from the metastable state of the stochastic dynamics. In this realm, we reveal that for sufficiently strong memory, a memory-induced (meta)stable state can emerge in the system. In the second regime, the waiting time distribution is assumed to have an infinite mean. Here, for bistable systems we find two distinct scaling regimes, separated by an exponentially long time which may strongly depend on the initial conditions of the system.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044132"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677362","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

Magnetic levitation in the field of a rotating dipole. 旋转偶极子磁场中的磁悬浮。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.045003

Grégoire Le Lay, Sarah Layani, Adrian Daerr, Michael Berhanu, Rémy Dolbeault, Till Person, Hugo Roussille, Nicolas Taberlet

引用次数: 0

Nonequilibrium microbial dynamics unveil a new macroecological pattern beyond Taylor's law. 非平衡微生物动力学揭示了超越泰勒定律的新宏观生态模式。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.044402

José Camacho-Mateu, Aniello Lampo, Saúl Ares, José A Cuesta

{"title":"Nonequilibrium microbial dynamics unveil a new macroecological pattern beyond Taylor's law.","authors":"José Camacho-Mateu, Aniello Lampo, Saúl Ares, José A Cuesta","doi":"10.1103/PhysRevE.110.044402","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044402","url":null,"abstract":"We introduce a comprehensive analytical benchmark, relying on Fokker-Planck formalism, to study microbial dynamics in the presence of both biotic and abiotic forces. In equilibrium, we observe a balance between the two kinds of forces, leading to no correlations between species abundances. This implies that real microbiomes, where correlations have been observed, operate out of equilibrium. Therefore, we analyze nonequilibrium dynamics, presenting an ansatz for an approximate solution that embodies the complex interplay of forces in the system. This solution is consistent with Taylor's law as a coarse-grained approximation of the relation between species abundance and variance, but implies subtler effects, predicting unobserved structure beyond Taylor's law. Motivated by this theoretical prediction, we refine the analysis of existing metagenomic data, unveiling a novel universal macroecological pattern. Finally, we speculate on the physical origin of Taylor's law: building upon an analogy with Brownian motion theory, we propose that Taylor's law emerges as a fluctuation-growth relation resulting from equipartition of environmental resources among microbial species.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044402"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677464","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

Point-cloud clustering and tracking algorithm for radar interferometry. 雷达干涉测量的点云聚类和跟踪算法。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.045207

Magnus F Ivarsen, Jean-Pierre St-Maurice, Glenn C Hussey, Devin R Huyghebaert, Megan D Gillies

{"title":"Point-cloud clustering and tracking algorithm for radar interferometry.","authors":"Magnus F Ivarsen, Jean-Pierre St-Maurice, Glenn C Hussey, Devin R Huyghebaert, Megan D Gillies","doi":"10.1103/PhysRevE.110.045207","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.045207","url":null,"abstract":"In data mining, density-based clustering, which entails classifying datapoints according to their distributions in some space, is an essential method to extract information from large datasets. With the advent of software-based radio, ionospheric radars are capable of producing unprecedentedly large datasets of plasma turbulence backscatter observations, and new automatic techniques are needed to sift through them. We present an algorithm to automatically identify and track clusters of radar echoes through time, using dbscan, a celebrated density-based clustering method for noisy point clouds. We demonstrate our algorithm's efficiency by tracking turbulent structures in the E-region ionosphere, the so-called radar aurora. Through conjugate auroral imagery, as well as in situ satellite observations, we demonstrate that the observed turbulent structures generally track the motion of auroras. What is more, the radar aurora bulk motions exhibit key qualities of auroral electric field enhancements that have previously been observed with various instruments. We present preliminary statistical results using our method, and briefly discuss the method's limitations and potential future adaptations.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-2","pages":"045207"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677469","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

Theory of stability of self-sustaining dc discharges at inception with application to negative corona. 自持直流放电开始时的稳定性理论，并应用于负电晕。

IF 2.2 3区物理与天体物理

Physical Review E Pub Date : 2024-10-01 DOI: 10.1103/PhysRevE.110.045201

P G C Almeida, G V Naidis, M S Benilov

{"title":"Theory of stability of self-sustaining dc discharges at inception with application to negative corona.","authors":"P G C Almeida, G V Naidis, M S Benilov","doi":"10.1103/PhysRevE.110.045201","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.045201","url":null,"abstract":"The inception of self-sustaining dc discharges is analyzed in terms of the bifurcation theory. The existence of a nonphysical solution with negative ion and electron densities must be taken into account in order to identify the bifurcation type. The bifurcation is transcritical for positive and negative corona discharges and, in more general terms, it is expected to be transcritical for all discharge configurations except for the parallel-plate discharge, where the bifurcation is pitchfork. General trends of the bifurcation theory suggest that the corona discharges should be stable immediately after the inception. This conclusion is tested numerically for negative coronas in atmospheric-pressure air in coaxial-cylinder geometry. Two independent approaches have been used: (1) study of linear stability against infinitesimal perturbations with the use of an eigenvalue solver, and (2) following the time development of finite perturbations with the use of a time-dependent solver. The numerical results agree with each other and with the theory. In particular, it is shown that the negative corona is stable, i.e., pulseless, immediately after the ignition. The loss of stability occurs through growth of harmonic perturbations, which subsequently evolve into Trichel pulses, and this happens on the ascending branch of the current-voltage characteristic, contrary to the popular concept of negative differential resistance. Results of the work are of theoretical interest and offer further insights into physics of negative corona discharges.","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-2","pages":"045201"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677487","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