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Concept

Masse négative

Publications associées (11)

A proof of the instability of AdS for the Einstein-massless Vlasov system

Georgios Moschidis

In recent years, the conjecture on the instability of Anti-de Sitter spacetime, put forward by Dafermos-Holzegel (Dynamic instability of solitons in 4 + 1 dimesnional gravity with negative cosmological constant, 2006. https://www.dpmms.cam.ac.uk/similar to ...

SPRINGER HEIDELBERG2022

Runaway electron modelling in the self-consistent core European Transport Simulator

Joan Decker

Relativistic runaway electrons are a major concern in tokamaks. Although significant theoretical development had been undertaken in recent decades, we still lack a self-consistent simulator that could simultaneously capture all aspects of this phenomenon. ...

IOP Publishing Ltd2019

Emergence of Friedmann Equation of Cosmology of a Flat Universe from the Time-Energy Uncertainty Principle

Farhad Rachidi-Haeri

Friedmann equation of cosmology is based on the field equations of general relativity. Its derivation is straight-forward once the Einstein’s field equations are given and the derivation is independent of quantum mechanics. In this paper, it is shown that ...

2017

Completing Lorentz violating massive gravity at high energies

Sergey Sibiryakov, Diego Blas Temino

Theories with massive gravitons are interesting for a variety of physical applications, ranging from cosmological phenomena to holographic modeling of condensed matter systems. To date, they have been formulated as effective field theories with a cutoff pr ...

Springer Verlag2015

More on cosmological constraints on spontaneous R-symmetry breaking models

We study the spontaneous R-symmetry breaking model and investigate the cosmological constraints on this model due to the pseudo Nambu-Goldstone boson, R-axion. We consider the R-axion which has relatively heavy mass in order to complement our previous work ...

Iop Publishing Ltd2014

On the effective operators for Dark Matter annihilations

Alexander Monin, Andrea Thamm, Andrea De Simone

We consider effective operators describing Dark Matter (DM) interactions with Standard Model fermions. In the non-relativistic limit of the DM field, the operators can be organized according to their mass dimension and their velocity behaviour, i.e. whethe ...

Iop Publishing Ltd2013

Electroacoustic metamaterials: achieving negative acoustic properties with shunt loudspeakers

Hervé Lissek

Acoustic metamaterials constitute a new class of structures that exhibit acoustic properties not readily available in nature. These properties can be a negative mass density, expressing the opposition of the acceleration of a particle to the application of ...

2013

Observation of multiple volume reflection by different planes in one bent silicon crystal for high-energy negative particles

Multiple volume reflection by different planes passing through the 〈111〉 axis in a bent silicon crystal was observed for the first time for 150 GeV/c negative particles, π- mesons, at one of the secondary beams of the CERN SPS. The beam of π- mesons was de ...

2011

First-principles study of high-field piezoelectricity in tetragonal PbTiO3

Anindya Roy, Massimiliano Stengel

We calculate from first principles the nonlinear piezoelectric response of ferroelectric PbTiO3 for the case of a polarization-enhancing electric field applied along the tetragonal axis. We focus mainly on the case of fixed in-plane lattice constants, corr ...

2010

Oxide charging and memory effects in suspended-gate FET

Mihai Adrian Ionescu, Nicolas Abelé

An original study of the dielectric charging in a suspended gate FET device (SG-FET) and its use for memory applications is reported. Combining a movable conductive gate with the ability to retain charge on top of the dielectric layer of FET device, a MEMS ...

2008

High resolution miniature rotary microactuator

Jean-Marc Breguet

For the development of high precision mobile microrobots with a size of about one cm3, capable of micromanipulation tasks, small and precise actuators have to be developed in order to provide the microrobot and its manipulation tools with the required degr ...

2004