Publications associées à Loi universelle de la gravitation

Liquid film instability of an internally coated horizontal tube

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière, Shahab Eghbali

We study numerically and theoretically the gravity-driven flow of a viscous liquid film coating the inner side of a horizontal cylindrical tube and surrounding a shear-free dynamically inert gaseous core. The liquid-gas interface is prone to the Rayleigh-P ...

AMER PHYSICAL SOC2023

Experimental and numerical investigation of the unbalance behavior of rigid rotors supported by spiral-grooved gas journal bearings

Jürg Alexander Schiffmann, Elia Iseli

The forced response of rigid rotors, supported by herringbone-grooved gas journal bearings are investigated numerically and experimentally. The rotor configurations are varied by using end cylinders, attached at both sides of the shaft. Three rotors with d ...

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD2022

Locally active globally stable dynamical systems: Theory, learning, and experiments

Aude Billard, Nadia Barbara Figueroa Fernandez

State-dependent dynamical systems (DSs) offer adaptivity, reactivity, and robustness to perturbations in motion planning and physical human-robot interaction tasks. Learning DS-based motion plans from non-linear reference trajectories is an active research ...

SAGE PUBLICATIONS LTD2022

Einstein-Cartan Portal to Dark Matter

Mikhail Chapochnikov, Andrey Shkerin, Inar Timiryasov, Sebastian Zell

It is well known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincare group, which puts gravity on the same footing as the standard model fields. The resulting theory-Einstein-Cartan gravity-inevitably ...

AMER PHYSICAL SOC2021

Quasi-stationary flow structure in turbidity currents

Giovanni De Cesare, Shun Nomura

A turbidity current is a particle-laden current driven by density differences due to suspended sediment particles. Turbidity currents can transport large amounts of sediment down slopes over great distances, and play a significant role in fluvial, lake and ...

IRTCES2020

A multidirectional gravity-assist algorithm that enhances locomotor control in patients with stroke or spinal cord injury

Auke Ijspeert, Grégoire Courtine, Marco Capogrosso, Jocelyne Bloch, Selin Anil, Joachim von Zitzewitz, Nicolas Francis Fumeaux, Jessica Lanini, Rubia van den Brand, Jean-Baptiste Mignardot

Gait recovery after neurological disorders requires remastering the interplay between body mechanics and gravitational forces. Despite the importance of gravity-dependent gait interactions and active participation for promoting this learning, these essenti ...

Amer Assoc Advancement Science2017

Stokes' third problem for Herschel-Bulkley fluids

Christophe Ancey, Belinda Margaret Bates

Herschel-Bulkley materials can be set in motion when a sufficiently high shear stress or body force is applied to them. We investigate the behaviour of a layer of Herschel-Bulkley fluid when it is suddenly tilted and subject to gravitational forces. The ma ...

Elsevier2017

Looking for dark matter trails in colliding galaxy clusters

Jean-Paul Richard Kneib, David Richard Harvey, Richard Massey

If dark matter interacts, even weakly, via non-gravitational forces, simulations predict that it will be preferentially scattered towards the trailing edge of the halo during collisions between galaxy clusters. This will temporarily create a non-symmetric ...

Oxford Univ Press2017

Enhanced discriminability for nonbiological motion violating the two-thirds power law

Olaf Blanke, Roy Salomon, Nathan Quentin Faivre, Laurène Véronique Vuillaume

The two-thirds power law describes the relationship between velocity and curvature in human motor movements. Interestingly, this motor law also affects visual motion perception, in which stimuli moving according to the two-thirds power law are perceived to ...

Association for Research in Vision and Ophthalmology (ARVO)2016

Adapting tilt corrections and the governing flow equations for steep, fully three-dimensional, mountainous terrain

Wolf Hendrik Huwald, Marc Parlange, Holly Jayne Oldroyd, Eric Richard Pardyjak

In recent studies of atmospheric turbulent surface exchange in complex terrain, questions arise concerning velocity-sensor tilt corrections and the governing flow equations for coordinate systems aligned with steep slopes. The standard planar-fit method, a ...

2016

Quantum limits on measurement and control of a mechanical oscillator

Vivishek Sudhir

The precision measurement of position has a long-standing tradition in physics. Cavendish's verification of the universal law of gravitation using a torsion pendulum, Perrin's confirmation of the atomic hypothesis via the precise measurement of the Brownia ...

EPFL2016

Enhanced robustness digital holographic microscopy for demanding environment of space biology

Christian Depeursinge, Jonas Kühn, Muhammed Fatih Toy, Marcel Egli, Stéphane Richard

We describe an optimized digital holographic microscopy system (DHM) suitable for high-resolution visualization of living cells under conditions of altered macroscopic mechanical forces such as those that arise from changes in gravitational force. Experime ...

2012

The Bounded Confidence Model Of Opinion Dynamics

Jean-Yves Le Boudec, Javier Gomez Serrano

The bounded confidence model of opinion dynamics, introduced by Deffuant et al, is a stochastic model for the evolution of continuous-valued opinions within a finite group of peers. We prove that, as time goes to infinity, the opinions evolve globally into ...

World Scientific Publishing2012

Proposed new probe of modified gravity

Alexey Boyarsky, Oleg Ruchayskiy

We suggest a new efficient way to constrain a certain class of large scale modifications of gravity. We show that the scale-free relation between density and size of dark matter halos, predicted within the ACDM model with Newtonian gravity, gets modified i ...

2011

On the effect of image denoising on galaxy shape measurements

Frédéric Courbin, Georges Meylan, Marc Gentile, Guldariya Nurbaeva

Weak gravitational lensing is a very sensitive way of measuring cosmological parameters, including dark energy, and of testing current theories of gravitation. In practice, this requires exquisite measurement of the shapes of billions of galaxies over larg ...

2011

The dam-break problem for Herschel-Bulkley viscoplastic fluids down steep flumes

Christophe Ancey, Steve Cochard

In this paper we investigate the dam-break problem for viscoplastic (Herschel- Bulkley) fluids down a sloping flume: a fixed volume of fluid initially contained in a reservoir is released onto a slope and flows driven by gravitational forces until these fo ...

2009

Cascading gravity: Extending the Dvali-Gabadadze-Porrati model to higher dimension

Michele Redi

We present a generalization of the Dvali-Gabadadze-Porrati scenario to higher codimensions which, unlike previous attempts, is free of ghost instabilities. The 4D propagator is made regular by embedding our visible 3-brane within a 4-brane, each with their ...

2008

Scaling of capillary, gravity and viscous forces affecting flow morphology in unsaturated porous media

Dani Or

Interplay between capillary, gravity and viscous forces in unsaturated porous media gives rise to a range of complex flow phenomena affecting morphology, stability and dynamics of wetting and drainage fronts. Similar average phase contents may result in si ...

2008

Models for piezoelectric sensor-actuator systems

Robert Dunsch

The miniaturization trend in industry requires micro devices for handling and sensing in a micro environment. As the size of the handled objects decreases and their fragility increases, the demand for sensors with higher force sensitivity and resolution gr ...

EPFL2007

Motion of gas bubbles, considered as massless bodies, affording deformations within a prescribed family of shapes, in an incompressible fluid under the action of gravitation and surface tension

A model allowing to describe motion and coalescence of gas bubbles in a liquid under the action of gravitation and surface tension is proposed. The shape of the bubbles is described by a pre-defined family of mappings, for example ellipsoids with a fixed v ...

2007