Publications associées à Applying combined field integral equation technique to analyze quasi-waveguide structures

Stochastic homogenization of degenerate integral functionals with linear growth

We study the limit behaviour of sequences of non-convex, vectorial, random integral functionals, defined on W1,1, whose integrands are ergodic and satisfy degenerate linear growth conditions. The latter involve suitable random, scale-dependent weight-funct ...

2023

On a Finite-Size Neuronal Population Equation

Valentin Marc Schmutz, Tilo Schwalger, Eva Löcherbach

Population equations for infinitely large networks of spiking neurons have a long tradition in theoret-ical neuroscience. In this work, we analyze a recent generalization of these equations to populations of finite size, which takes the form of a nonlinear ...

SIAM PUBLICATIONS2023

Unraveling looping efficiency of stochastic Cosserat polymers

Giulio Corazza, Raushan Singh

Understanding looping probabilities, including the particular case of ring closure or cyclization, of fluctuating polymers (e.g., DNA) is important in many applications in molecular biology and chemistry. In a continuum limit the configuration of a polymer ...

AMER PHYSICAL SOC2022

Normalized Gaussian path integrals

Giulio Corazza

Path integrals play a crucial role in describing the dynamics of physical systems subject to classical or quantum noise. In fact, when correctly normalized, they express the probability of transition between two states of the system. In this work, we show ...

AMER PHYSICAL SOC2020

Symplectic dynamical low rank approximation of wave equations with random parameters

Fabio Nobile, Eleonora Musharbash, Eva Vidlicková

In this paper we propose a dynamical low-rank strategy for the approximation of second order wave equations with random parameters. The governing equation is rewritten in Hamiltonian form and the approximate solution is expanded over a set of 2S dynamical ...

2020

Time and space adaptivity of the wave equation discretized in time by a second-order scheme

Marco Picasso, Olga Gorynina

The aim of this paper is to obtain a posteriori error bounds of optimal order in time and space for the linear second-order wave equation discretized by the Newmark scheme in time and the finite element method in space. An error estimate is derived in the ...

2019

On Jump-Diffusive Driving Noise Sources: Some Explicit Results and Applications

Max-Olivier Hongler, Roger Filliger

We study some linear and nonlinear shot noise models where the jumps are drawn from a compound Poisson process with jump sizes following an Erlang-m distribution. We show that the associated Master equation can be written as a spatial mth order partial dif ...

Springer2019

Stochastic partial differential equations driven by Lévy white noises : generalized random processes, random field solutions and regularity

Thomas Marie Jean-Baptiste Humeau

We study various aspects of stochastic partial differential equations driven by Lévy white noise. This driving noise, which is a generalization of Gaussian white noise, can be viewed either as a generalized random process or as an independently scattered r ...

EPFL2017

Optical second harmonic generation from nanostructured graphene: a full wave approach

Olivier Martin, Gabriel David Bernasconi, Raziman Thottungal Valapu, Jérémy Butet, Bruno Majérus

Optical second harmonic generation (SHG) from nanostructured graphene has been studied in the framework of classical electromagnetism using a surface integral equation method. Single disks and dimers are considered, demonstrating that the nonlinear convers ...

2017

Dynamical Low Rank approximation of PDEs with random parameters

Eleonora Musharbash

In this work, we focus on the Dynamical Low Rank (DLR) approximation of PDEs equations with random parameters. This can be interpreted as a reduced basis method, where the approximate solution is expanded in separable form over a set of few deterministic b ...

EPFL2017

Path integral approach to the quantum fidelity amplitude

Jiri Vanicek

The Loschmidt echo is a measure of quantum irreversibility and is determined by the fidelity amplitude of an imperfect time-reversal protocol. Fidelity amplitude plays an important role both in the foundations of quantum mechanics and its applications, suc ...

Royal Soc2016

Yield stress modelling of doped alumina suspensions for applications in freeze granulation: towards dry pressed transparent ceramics

Paul Bowen, Michael Stuer

Rheology of powder suspensions is a key factor in many processing routes, and better understanding of the parameters that control the rheology improves technical progress by reducing the empirical factors in the formulation of powder slurries. The strict r ...

2012

Infinite integrals with the weighted averages algorithm

Juan Ramon Mosig, Athanasios Polymeridis

A new version of the weighted averages (WA) algorithm, called generalized WA, is introduced. Generalized WA exhibit a more compact formulation, devoid of iterative and recursive steps, and a wider range of applications. It is more robust, as it provides a ...

2011

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

Contribution to Integral Equation Techniques for Solving Electromagnetic Problems

Sergio Lopez Pena

Surface Mixed Potential Integral Equation (MPIE) formulations together with the Method of Moments (MoM) are widely used to solve electromagnetic problems. An accurate evaluation of the Green functions (GF) associated to the integral equation and of the cou ...

EPFL2010

Full-wave analysis of photonic-crystal structures with multi quantum well active region

Banafsheh Abasahl

In this paper, a semi-classical formulation for modeling photonic-crystal (PC) structures with a four-layer multi quantum well (MQW) active region is presented. The formulation treats the electromagnetic fields as a classical entity, while employing the qu ...

2010

Combined Field Integral Equation Technique to Model Fine Slots Embedded in Laterally Shielded Multilayered Media

Juan Ramon Mosig, Michael Mattes, Laleh Golestanirad

This paper presents the details of development and computer implementation of Combined Field Integral Equation (CFIE) technique used in the framework of Method of Moments to address the problem of simulating fine slots appearing in grounded screens embedde ...

2009

Introducing symmetry conditions in the integral equation technique applied to quasi-waveguide structures

Juan Ramon Mosig, Michael Mattes, Laleh Golestanirad

Integral Equation (IE) formulation solved by Method of Moments may be used efficiently to address the problem of quasi-waveguide structures, i.e. structures consisting of a main waveguide with a constant cross section that may bear an arbitrary number of p ...

2009

Unified formulation for Reissner-Mindlin plates: a comparison with numerical results

Luca Tassinari

Analytical solutions to problems of solids mechanics are useful to test the accuracy and the precision of the numerical approaches. Problems such as shear locking or boundary layer can be better understood with the help of analytical solutions. However, it ...

IASS Symposium 2009, Valencia, Spain2009

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