Concept

Schwinger's quantum action principle

Related publications (10)

Supersymmetries in nonequilibrium Langevin dynamics

Stochastic phenomena are often described by Langevin equations, which serve as a mesoscopic model for microscopic dynamics. It has been known since the work of Parisi and Sourlas that reversible (or equilibrium) dynamics present supersymmetries (SUSYs). Th ...

2021

A gyrokinetic model for the plasma periphery of tokamak devices

Paolo Ricci, Paolo De Los Rios, Rogério Manuel Cabete De Jesus Jorge, Baptiste Jimmy Frei

A gyrokinetic model is presented that can properly describe large and small amplitude electromagnetic fluctuations occurring on scale lengths ranging from the electron Larmor radius to the equilibrium perpendicular pressure gradient scale length, and the a ...

2020

Precision theoretical methods for large-scale structure of the Universe

Mikhail Ivanov

We develop new analytic methods to accurately describe the formation of cosmic large-scale structure. These methods are based on the path integral formalism and allows one to efficiently address a number of long-standing problems in the field. We describe ...

EPFL2019

Hydrogen dynamics in solid formic acid: insights from simulations with quantum colored-noise thermostats

Venkat Kapil

With an increase of computational capabilities, ab initio molecular dynamics becomes the natural choice for exploring the nuclear dynamics of solids. As based on classical mechanics, the validity of this approach is, in-principle, limited to the high-T reg ...

IOP PUBLISHING LTD2018

Accelerating path integral evaluation of equilibrium and kinetic isotope effects

Konstantin Karandashev

Investigating the effect of isotope substitution on equilibrium and kinetic properties of molecules has become an important tool for estimating the importance of nuclear quantum effects. In this work, we discuss calculating both equilibrium and kinetic iso ...

EPFL2018

Force-based higher-order beam element with flexural-shear-torsional interaction in 3D frames. Part II: Applications

João Saraiva Esteves Pacheco de Almeida

The specific features of the proposed force-based formulation derived in the companion paper, which is applied for the first time to higher-order beam theories, are herein thoroughly validated. Introductory numerical examples illustrate the influence of me ...

Elsevier2015

Three applications of path integrals: equilibrium and kinetic isotope effects, and the temperature dependence of the rate constant of the [1,5] sigmatropic hydrogen shift in (Z)-1,3-pentadiene

Jiri Vanicek, Tomas Zimmermann

Recent experiments have confirmed the importance of nuclear quantum effects even in large biomolecules at physiological temperature. Here we describe how the path integral formalism can be used to describe rigorously the nuclear quantum effects on equilibr ...

Springer Verlag2010

Looping probabilities of elastic chains: A path integral approach

John Maddocks, Ludovica Cotta-Ramusino

We consider an elastic chain at thermodynamic equilibrium with a heat bath, and derive an approximation to the probability density function, or pdf, governing the relative location and orientation of the two ends of the chain. Our motivation is to exploit ...

2010

A path integral formalism of DNA looping probability

Ludovica Cotta-Ramusino

In this thesis we describe a path integral formalism to evaluate approximations to the probability density function for the location and orientation of one end of a continuum polymer chain at thermodynamic equilibrium with a heat bath. We concentrate on th ...

EPFL2008

The Casimir force in the semi-classical regime

The present thesis is devoted to a detailed study of the Casimir force exerting between two parallel metallic plates whose conducting behaviour is described on the microscopic level. In the semi-classical regime, which corresponds to large separations and ...

EPFL2006

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.