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Maximum entropy models are increasingly being used to describe the collective activity of neural populations with measured mean neural activities and pairwise correlations, but the full space of probability distributions consistent with…

Biological Physics · Physics 2017-08-22 Badr F. Albanna , Christopher Hillar , Jascha Sohl-Dickstein , Michael R. DeWeese

In this paper, we take a data-driven approach and apply machine learning to the moment closure problem for radiative transfer equation in slab geometry. Instead of learning the unclosed high order moment, we propose to directly learn the…

Numerical Analysis · Mathematics 2022-02-09 Juntao Huang , Yingda Cheng , Andrew J. Christlieb , Luke F. Roberts

Radiative transfer (RT) simulations are a powerful tool that enables the calculation of synthetic images of a wide range of astrophysical objects. These simulations are often based on the Monte Carlo (MC) method, as it provides the needed…

Instrumentation and Methods for Astrophysics · Physics 2023-11-23 Anton Krieger , Sebastian Wolf

This is the second paper in a series in which we develop machine learning (ML) moment closure models for the radiative transfer equation (RTE). In our previous work \cite{huang2021gradient}, we proposed an approach to directly learn the…

Numerical Analysis · Mathematics 2021-06-01 Juntao Huang , Yingda Cheng , Andrew J. Christlieb , Luke F. Roberts , Wen-An Yong

In the framework of a two-moment photo-hydrodynamic modelling of radiation transport, we introduce a concept for the determination of effective radiation transport coefficients based on the minimization of the local entropy production rate…

Statistical Mechanics · Physics 2014-11-18 Thomas Christen , Frank Kassubek

If moments of singular measures are passed as inputs to the entropy maximization procedure, the optimization algorithm might not terminate. The framework developed in our previous paper demonstrated how input moments of measures, on a broad…

Complex Variables · Mathematics 2020-05-08 Marko Budišić , Mihai Putinar

Observations and magnetohydrodynamic simulations of solar and stellar atmospheres reveal an intermittent behavior or steep gradients in physical parameters, such as magnetic field, temperature, and bulk velocities. The numerical solution of…

Solar and Stellar Astrophysics · Physics 2019-03-22 Gioele Janett

We consider the problem of computing first-passage time distributions for reaction processes modelled by master equations. We show that this generally intractable class of problems is equivalent to a sequential Bayesian inference problem…

Computational Physics · Physics 2017-11-29 David Schnoerr , Botond Cseke , Ramon Grima , Guido Sanguinetti

A new simple method for the first order phase transition kinetics is suggested. The metastable phase consumption can be imagined in frames of the modisperse approximation for the distribution of the droplets sizes. In all situations of the…

Atmospheric and Oceanic Physics · Physics 2007-05-23 V. Kurasov

Quantum angular moment transport schemes are an important avenue toward describing neutrino flavor mixing phenomena in dense astrophysical environments such as supernovae and merging neutron stars. Successful implementation will require new…

High Energy Physics - Phenomenology · Physics 2025-03-11 Julien Froustey , James P. Kneller , Gail C. McLaughlin

We propose a high-order stochastic-statistical moment closure model for efficient ensemble prediction of leading-order statistical moments and probability density functions in multiscale complex turbulent systems. The statistical moment…

Numerical Analysis · Mathematics 2023-06-21 Di Qi , Jian-Guo Liu

Modeling correctly the transport of neutrinos is crucial in some astrophysical scenarios such as core-collapse supernovae and binary neutron star mergers. In this paper, we focus on the truncated-moment formalism, considering only the first…

General Relativity and Quantum Cosmology · Physics 2023-05-30 Manuel R. Izquierdo , Lorenzo Pareschi , Borja Miñano , Joan Massó , Carlos Palenzuela

The moments of spatial probabilistic systems are often given by an infinite hierarchy of coupled differential equations. Moment closure methods are used to approximate a subset of low order moments by terminating the hierarchy at some order…

Machine Learning · Computer Science 2019-05-30 Oliver K. Ernst , Tom Bartol , Terrence Sejnowski , Eric Mjolsness

By controlling in real-time the variance of the radiation pressure exerted on an optically trapped microsphere, we engineer temperature protocols that shortcut thermal relaxation when transferring the microsphere from one thermal…

In dynamical system theory, the process of obtaining a reduced-order approximation of the high-order model is called model order reduction. The closeness of the reduced-order model to the original model is generally gauged by using system…

Systems and Control · Electrical Eng. & Systems 2023-03-07 Umair Zulfiqar , Xin Dua , Qiuyan Song , Muwahida Liaquat , Victor Sreeram

We describe a new algorithm to solve the time dependent, frequency integrated radiation transport (RT) equation implicitly, which is coupled to an explicit solver for equations of magnetohydrodynamics (MHD) using {\sf Athena++}. The…

Instrumentation and Methods for Astrophysics · Physics 2021-04-07 Yan-Fei Jiang

Dissipative quantum systems are frequently described within the framework of the so-called "system-plus-reservoir" approach. In this work we assign their description to the Maximum Entropy Formalism and compare the resulting thermodynamic…

Statistical Mechanics · Physics 2017-01-04 Lisan M. M. Durão , Amir O. Caldeira

This study investigates numerical methods to solve nonlinear transport problems characterized by various sorption isotherms with a focus on the Freundlich type of isotherms. We describe and compare second order accurate numerical schemes,…

Numerical Analysis · Mathematics 2025-07-22 Dagmar Zakova , Peter Frolkovic

This paper presents an entropy based adaptive measurement sequence strategy for quantum sensing of magnetic fields. To physically ground our ideas we consider a sensor employing a nitrogen vacancy center in diamond, however our approach is…

We propose a hybrid moment method for the multi-scale kinetic equations in the framework of the regularized moment method [7]. In this method, the fourth order moment system is chosen as the governing equations in the fluid region. When…

Computational Physics · Physics 2020-04-14 Weiming Li , Peng Song , Yanli Wang