Search results for "Free fall"

showing 3 items of 3 documents

Towards a test of the weak equivalence principle of gravity using anti-hydrogen at CERN

2016

International audience; The aim of the GBAR (Gravitational Behavior of Antimatter at Rest) experiment is to measure the free fall acceleration of an antihydrogen atom, in the terrestrial gravitational field at CERN and therefore test the Weak Equivalence Principle with antimatter. The aim is to measure the local gravity with a 1% uncertainty which can be reduced to few parts of 10-3.

Free fallGravity (chemistry)Particle physicsPhysics::General PhysicsAntimatterCERN LabGravityacceleration measurementterrestrial gravitational fieldfree fall acceleration01 natural sciencesantihydrogen: accelerationweak equivalence principle010305 fluids & plasmasparticle trapsAtomic measurementsGravitationGeneral Relativity and Quantum Cosmologyhydrogen: ionGravitational fieldLaser transitionsAtom (measure theory)0103 physical sciencesPhysics::Atomic and Molecular Clusters[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsAntihydrogenantihydrogen atomPhysicsIonsatomProductionEquivalence principle (geometric)laserequivalence principleAntimatter[PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]talk: Ottawa 2016/07/10gravitation: localhydrogen ionsCoolingGravitation
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Violation of the equivalence principle from light scalar dark matter

2018

In this paper, we study the local observational consequences of a violation of the Einstein Equivalence Principle induced by models of light scalar Dark Matter (DM). We focus on two different models where the scalar field couples linearly or quadratically to the standard model of matter fields. For both these cases, we derive the solutions of the scalar field. We also derive from first principles the expressions for two types of observables: (i) the local comparison of two atomic sensors that are differently sensitive to the constants of Nature and (ii) the local differential acceleration between two test-masses with different compositions. For the linear coupling, we recover that the signa…

General relativityAtomic Physics (physics.atom-ph)Dark matteralternative theories of gravityFOS: Physical sciencesGeneral Relativity and Quantum Cosmology (gr-qc)local position invariance01 natural sciencesGeneral Relativity and Quantum CosmologyPhysics - Atomic Physicsspace-time: oscillationdark matter: couplingGravitationTheoretical physicsHigh Energy Physics - Phenomenology (hep-ph)Gravitational field0103 physical sciencesDark Matteruniversalityequivalence principle: violationdark matter: scalarEquivalence principle010306 general physicsmodified gravityPhysics010308 nuclear & particles physicsScalar (physics)Yukawa potentialtorsioncoupling: linearuniversality of free fall[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph]field theory: scalarHigh Energy Physics - Phenomenologypotential: YukawaGeneral relativitytests of gravitygravitation[SDU]Sciences of the Universe [physics][PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph][PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]expansion: accelerationScalar field
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Time-Frequency Characteristics of In-Home Radio Channels Influenced by Activities of the Home Occupant

2019

While aging is a serious global concern, in-home healthcare monitoring solutions are limited to context-aware systems and wearable sensors, which may easily be forgotten or ignored for privacy and comfort reasons. An emerging non-wearable fall detection approach is based on processing radio waves reflected off the body, who has no active interaction with the system. This paper reports on an indoor radio channel measurement campaign at 5.9 GHz, which has been conducted to study the impact of fall incidents and some daily life activities on the temporal and spectral properties of the indoor channel under both line-of-sight (LOS) and obstructed-LOS (OLOS) propagation conditions. The time-frequ…

device-free fall detectionComputer scienceReal-time computingWearable computerVDP::Information and communication science: 42002 engineering and technologylcsh:Chemical technology01 natural sciencesBiochemistryArticleAnalytical ChemistryDoppler power spectral density0202 electrical engineering electronic engineering information engineeringlcsh:TP1-1185Electrical and Electronic EngineeringInstrumentationnon-stationary radio channels010401 analytical chemistry020206 networking & telecommunicationsAtomic and Molecular Physics and Optics0104 chemical sciencesTime–frequency analysisspectrogram analysisVDP::Informasjons- og kommunikasjonsvitenskap: 420Radio waveCommunication channelambient-assisted livingSensors (Basel, Switzerland)
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