Gravitational Wave Bursts Produced by Cosmic ... - Florent Robinet

be measured with a Michelson interferometer. L. L. L+dL. L-dL. + x. To be able to detect gravitational waves with h < 10 – 21 the basic concept of the Michelson.
3MB taille 3 téléchargements 233 vues
Fundamental Physics Laws : Gravity, Lorentz symmetry and Quantum Gravity - June 2010

Gravitational Wave Bursts Produced by Cosmic Strings Cusps Florent Robinet

Gravitational Waves Gravitational waves = "ripples" in space­time Weak field approximation :

g = h 

∣h  ∣≪1

Wave equation, speed c Solution with 2 d.o.f. : polarizations  h+ and hx  Black hole merger

Dimensionless amplitude given by h

Production of gravitational waves 2 6 5 R c 2 s v ℒ = G R c

  

A good GW source : ­ is compact and massive ­ is asymmetric ­ has a relativistic speed

Lab production : 

h ~ 10 – 39

Astrophysical sources :  h ~ 10 – 21

Fundamental Physics Laws : Gravity, Lorentz symmetry and Quantum Gravity - June 2010

Gravitational Wave Sources Supernovae (asymmetric core  bounce) 

Pulsars (asymmetric rotations,  instabilities) 

Compact binary  coalescence of neutron  stars &/or black holes Cosmic string cusps

The unexpected Stochastic background

?

Fundamental Physics Laws : Gravity, Lorentz symmetry and Quantum Gravity - June 2010

They are real !

Binary pulsar PSR 1913+16 The decrease of the orbital period has been studied over more than 20 years It can be fully explained by the energy loss due to the emission of gravitational waves Nobel Prize 1993 Hulse-Taylor

Fundamental Physics Laws : Gravity, Lorentz symmetry and Quantum Gravity - June 2010

Detection of Gravitational Waves L+dL +

L L

x

L-dL

The interferometry seems to be  appropriate Differential length variations can  be measured with a Michelson  interferometer

Fundamental Physics Laws : Gravity, Lorentz symmetry and Quantum Gravity - June 2010

Detection of Gravitational Waves L+dL +

L L

L-dL

x

The interferometry seems to be  appropriate Differential length variations can  be measured with a Michelson  interferometer

To be able to detect gravitational waves with  h