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The response of thermodynamic systems perturbed out of an equilibrium steady-state is described by the reciprocal and the fluctuation-dissipation relations. The so-called fluctuation theorems extended the study of fluctuations far beyond…

Statistical Mechanics · Physics 2020-02-21 Matteo Polettini , Massimiliano Esposito

Fractal channels have significant applications in fields such as microfluidic chips and in vitro diagnostics. However, there is currently insufficient understanding and recognition of fluid flow within fractal channels. In this paper, the…

Fluid Dynamics · Physics 2024-09-20 Jun Hu , Zhan-Long Wang

Faraday rotation measure (RM) synthesis is a well-known approach originated in Burn (1966) and later developed by Brentjens \& de Bruyn (2005) for studying magnetic fields. This work presents a complementary approach--the polarization…

High Energy Astrophysical Phenomena · Physics 2025-08-22 Yawen Xiao , Jianfu Zhang , Alex Lazarian , Dmitri Pogosyan

The quantum dynamics of fermionic or bosonic many-body systems following external excitation can be successfully studied using two-time nonequilibrium Green's functions (NEGF) or single-time reduced density matrix methods. Approximations…

Strongly Correlated Electrons · Physics 2022-07-12 Erik Schroedter , Jan-Philip Joost , Michael Bonitz

We present a method for reconstructing cosmological densityn for and velocity fields using the Lagrangian Zel'dovich formalism. . The method involves finding the least action solution for straight line particle paths in an evolving density…

Astrophysics · Physics 2015-06-24 R. A. C. Croft , E. Gaztanaga

An analytic approximation to the mass function for gravitationally bound objects is presented. We base on the Zel'dovich approximation to extend the Press-Schechter formalism to a nonspherical dynamical model. A simple extrapolation of that…

Astrophysics · Physics 2009-10-30 Jounghun Lee , Sergei F. Shandarin

We use the multifractal detrended fluctuation analysis (MF-DFA) to study the electrical discharge current fluctuations in plasma and show that it has multifractal properties and behaves as a weak anti-correlated process. Comparison of the…

Statistical Mechanics · Physics 2009-04-04 S. Kimiagar , M. Sadegh Movahed , S. Khorram , S. Sobhanian , M. Reza Rahimi Tabar

We propose the frozen Gaussian approximation for computation of high frequency wave propagation. This method approximates the solution to the wave equation by an integral representation. It provides a highly efficient computational tool…

Numerical Analysis · Mathematics 2011-03-16 Jianfeng Lu , Xu Yang

In industrial and environmental monitoring, achieving real-time and precise fluid flow measurement remains a critical challenge. This study applies linear quantization in FPGA-based soft sensors for fluid flow estimation, significantly…

Machine Learning · Computer Science 2025-10-28 Tianheng Ling , Julian Hoever , Chao Qian , Gregor Schiele

We present a comparative study of six different methods for reversing the gravitational evolution of a cosmological density field to recover the primordial fluctuations: linear theory, the Gaussianization mapping scheme, two different…

Astrophysics · Physics 2009-10-30 Vijay K. Narayanan , Rupert A. C. Croft

The response of a one-dimensional fermion system is investigated using Density Functional Theory (DFT) within the Local Density Approximation (LDA), and compared with exact results. It is shown that DFT-LDA reproduces surprisingly well some…

Strongly Correlated Electrons · Physics 2008-10-30 Stefan Schenk , Michael Dzierzawa , Peter Schwab , Ulrich Eckern

We calculate the cosmological evolution of the 1-point probability distribution function (PDF), using an analytic approximation that combines gravitational perturbation theory with the Edgeworth expansion of the PDF. Our method applies…

Astrophysics · Physics 2009-10-22 R. Juszkiewicz , D. Weinberg , P. Amsterdamski , M. Chodorowski , F. Bouchet

We characterize the long time behaviour of a discrete-in-time approximation of the volume preserving fractional mean curvature flow. In particular, we prove that the discrete flow starting from any bounded set of finite fractional perimeter…

Analysis of PDEs · Mathematics 2023-01-10 De Gennaro Daniele , Andrea Kubin , Anna Kubin

We critically examine how the evolution of the matter density field in cosmological simulations is affected by details of setting up initial conditions. We show that it is non-trivial to realise an initial distribution of matter in…

Astrophysics · Physics 2009-11-07 Naoki Yoshida , Naoshi Sugiyama , Lars Hernquist

We use, for the first time, the Detrend Fluctuation Analysis (DFA) to study the correlation properties of the transmitted flux fluctuations, in the Lyman-$\alpha$ (Ly$\alpha$) Forest along the lines of sight (LOS) to QSOs, at different…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-23 R. N. Guimarães , P. Petitjean , E. Rollinde , S. G. Djorgovski , M. S. da Silva , M. A Moret

A simplified model of natural convection, similar to the Lorenz (1963) system, is compared to computational fluid dynamics simulations in order to test data assimilation methods and better understand the dynamics of convection. The…

Dynamical Systems · Mathematics 2012-04-23 Kameron Decker Harris , El Hassan Ridouane , Darren L. Hitt , Christopher M. Danforth

Stochastic thermodynamics is an important development in the direction of finding general thermodynamic principles for non-equilibrium systems. We believe stochastic thermodynamics has the potential to benefit from the measure-theoretic…

Statistical Mechanics · Physics 2023-07-06 Annwesha Dutta , Saikat Sarkar

Understanding the physics of nonequilibrium systems remains as one of the major challenges of theoretical physics. This problem can be cracked in part by investigating the macroscopic fluctuations of the currents characterizing…

Statistical Mechanics · Physics 2014-03-18 Pablo I. Hurtado , Carlos P. Espigares , Jesus J. del Pozo , Pedro L. Garrido

We discuss the relation between the output of Newtonian N-body simulations on scales that approach or exceed the particle horizon to the description of General Relativity. At leading order, the Zeldovich approximation is correct on large…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-27 Cornelius Rampf , Gerasimos Rigopoulos , Wessel Valkenburg

We consider exact solutions to the problem of ballistic aggregation in a flow of adhesive particles, providing a model for large-scale structure formation in cosmology within the framework of the Zel'dovich approximation. Two different…

Pattern Formation and Solitons · Physics 2007-07-19 A. Andrievskii , S. Gurbatov , A. Sobolevskii