Publications related to H-theorem

Mean-field transport equations and energy theorem for plasma edge turbulent transport

This paper establishes a mean-field equation set and an energy theorem to provide a theoretical basis in view of the development of self-consistent, physics-based turbulent transport models for mean-field transport codes. A rigorous averaging procedure ide ...

Cambridge University Press2024

Equilibrium β-limits dependence on bootstrap current in classical stellarators

Jonathan Graves, Joaquim Loizu Cisquella, Antoine Baillod

While it is important to design stellarators with high magnetohydrodynamic stability β-limit, it is also crucial to ensure that good magnetic surfaces exist in a large range of β values. As β increases, pressure-driven currents perturb the vacuum magnetic ...

Cambridge University Press2023

Small Obstacle in a Large Polar Flock

Ignacio Pagonabarraga Mora

We show that arbitrarily large polar flocks are susceptible to the presence of a single small obstacle. In a wide region of parameter space, the obstacle triggers counterpropagating dense bands leading to reversals of the flow. In very large systems, these ...

AMER PHYSICAL SOC2022

Entropic Fokker-Planck kinetic model

Mohammadhossein Gorji

The diffusion limit of kinetic systems has been subject of numerous studies since prominent works of Lebowitz et al. [1] and van Kampen [2]. More recently, the topic has seen a fresh interest from the rarefied gas simulation perspective. In particular, Fok ...

2021

Cryogenic MOSFET Modeling for Large-Scale Quantum Computing

Arnout Lodewijk M Beckers

Promising results of state-of-the-art quantum computers fuel a world-wide effort in academic and private research laboratories to scale up the number of qubits and improve their characteristics in large arrays. To meet the scale-up challenge, innovative mi ...

EPFL2021

Gaussian Process Regression for Maximum Entropy Distribution

Mohammadhossein Gorji, Mohsen Sadr

Maximum-Entropy Distributions offer an attractive family of probability densities suitable for moment closure problems. Yet finding the Lagrange multipliers which parametrize these distributions, turns out to be a computational bottleneck for practical clo ...

2020

Coarse-grained entropy production with multiple reservoirs: Unraveling the role of time scales and detailed balance in biology-inspired systems

Daniel Maria Busiello, Amos Maritan, Deepak Gupta

A general framework to describe a vast majority of biology-inspired systems is to model them as stochastic processes in which multiple couplings are in play at the same time. Molecular motors, chemical reaction networks, catalytic enzymes, and particles ex ...

2020

First-principles calculations of charge carrier mobility and conductivity in bulk semiconductors and two-dimensional materials

Samuel Poncé, Feliciano Giustino

One of the fundamental properties of semiconductors is their ability to support highly tunable electric currents in the presence of electric fields or carrier concentration gradients. These properties are described by transport coefficients such as electro ...

IOP PUBLISHING LTD2020

Entropy production for coarse-grained dynamics

Daniel Maria Busiello, Amos Maritan

Systems out of equilibrium exhibit a net production of entropy. We study the dynamics of a stochastic system represented by a Master equation (ME) that can be modeled by a Fokker-Planck equation in a coarse-grained, mesoscopic description. We show that the ...

2019

Kinetic approach to the Schwinger effect during inflation

Oleksandr Sobol

Using the kinetic approach, we study the impact of the charged particle dynamics due to the Schwinger effect on the electric field evolution during inflation. As a simple model of the electric field generation, we consider the kinetic coupling of the elect ...

American Physical Society2019

Electrical conductivity of hot Abelian plasma with scalar charge carriers

Oleksandr Sobol

We study the electrical conductivity of hot Abelian plasma containing scalar charge carriers in the leading logarithmic order in coupling constant alpha using the Boltzmann kinetic equation. The leading contribution to the collision integral is due to the ...

American Physical Society2019

Gaussian Process Regression for Maximum Entropy Distribution

Mohsen Sadr

Maximum-Entropy Distributions offer an attractive family of probability densities suitable for moment closure problems. Yet finding the Lagrange multipliers which parametrize these distributions, turns out to be a computational bottleneck for practical clo ...

2019

Approximating Matsubara dynamics using the planetary model: Tests on liquid water and ice

Michele Ceriotti, Michael John Willatt

Matsubara dynamics is the quantum-Boltzmann-conserving classical dynamics which remains when real-time coherences are taken out of the exact quantum Liouvillian [T. J. H. Hele et al., J. Chem. Phys. 142, 134103 (2015)]; because of a phase-term, it cannot b ...

2018

Unravelling the precipitation pathway of biorelevant minerals: from fundamental studies to biomedical applications

Agnese Carino

The formation pathway of biominerals archetypes, namely calcium carbonate (CaC) and calcium phosphates (CaPs), was investigated using a multidisciplinary approach. The time-resolved analytical data were collected using a controlled-composition method and i ...

EPFL2018

Dynamics of photoexcited Ba+ cations in 4He nanodroplets

Marcel Drabbels, Xiaohang Zhang, Alberto Hernando de Castro

We present a joint experimental and theoretical study on the desolvation of Ba+ cations in 4He nanodroplets excited via the 6p 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba+ cations and Ba+Hen exciplexes wit ...

American Institute of Physics2016

Nuclear Quantum Effects in Water at the Triple Point: Using Theory as a Link Between Experiments

Michele Ceriotti, Bingqing Cheng

One of the most prominent consequences of the quantum nature of light atomic nuclei is that their kinetic energy does not follow a Maxwell-Boltzmann distribution. Deep inelastic neutron scattering (DINS) experiments can measure this effect. Thus, the nucle ...

Amer Chemical Soc2016

Flexoelectric effect in finite samples

Alexander Tagantsev

Static flexoelectric effect in a finite sample of a solid is addressed in terms of phenomenological theory for the case of a thin plate subjected to bending. It has been shown that despite an explicit asymmetry inherent to the bulk constitutive electromech ...

American Institute of Physics2012

Energy relaxation in one-dimensional polariton condensates

Vincenzo Savona, Timothy Chi Hin Liew

We study the kinetics of polariton condensation accounting for the condensation process as well as the energy relaxation of condensed polaritons due to their scattering with phonons and excitons. By assuming a Boltzmann kinetic description of the scatterin ...

2010

Extension of a recent method for obtaining exact solutions of the Bruce and Klute equation

David Andrew Barry

A recent method based on a specific power-law relationship between the matric potential head and the Boltzmann variable was presented by Prevedello et. al. (2008). Here, this relationship was generalized to a range of powers, and the solution extended to i ...

2010

Linearized model Fokker-Planck collision operators for gyrokinetic simulations. II. Numerical implementation and tests

Paolo Ricci

A set of key properties for an ideal dissipation scheme in gyrokinetic simulations is proposed, and implementation of a model collision operator satisfying these properties is described. This operator is based on the exact linearized test-particle collisio ...

American Institute of Physics2009