new optical tests of relativity on earth and in...

New Optical Tests of Relativityon Earth and in Space

38th Recontres de Moriond, March 2003, Les Arcs, FranceAchim Peters

Contents

OPTIS – a satellite test of Special and General Relativity

A modern Michelson-Morley experimentusing cryogenic optical resonators (COREs)

Motivation

Results and prospects

Summary

Motivation

Relativity and Quantum Mechanicsare the foundation of modern physics

Improved technology makes new tests possible

Unified theories (String-theory, etc...)predict violations of Special Relativity

New frameworks for describing general violations of Special Relativity have been developed recently

Theory of Relativity

General Relativity (Einstein 1915): gravitation

Special Relativity (Einstein 1904)

velocityinvariance

isotropy universalityof free fall

local positioninvariance

time dilation

Experimental limits (2000)

! Velocity invariance ∆c/c < 2.10-13 |A| < 7.10-5

(Hils and Hall, 1990)

! Isotropy ∆c/c < 6.10-15 |B| < 6.10-9

(Brillet and Hall, 1979)

! Time dilation measurement violation < 10-7

(Isaak, 1970, Riis et al. 1988)

! Mansouri-Sexl test theory:

Assumed preferred frame: microwave background

Lorentz transformations confirmed at 7.10-5 level

∆cc = A

v2

c2 + Bv2

c2 sin2 θ

MM-experiments old & new

Frequency stabilization to a cavity

laser 1

PD

BS

servo

L

stable referencecavity

frequency analysis

Kennedy-Thorndike experiment

c

comparison

atomic clock

velocity of laboratory

Movement of Earth in space

Why Sapphire COREs ?

Low thermal expansion coefficient:Sapphire @ 1.5 K: 2·10-12 / KULE @ 300 K: 1·10-8 / K

Pure crystalline material at cryogenic temperatures:No (or very small) relaxation processes

Very high long-term stabilty: < 20 Hz / day (vs ~ 5 kHy / day for ULE @ 300 K)

Performance of COREs

Analysis of beatnote measurements between independent free-beam- or fiber-coupled CORES

MM-experiment using COREs

MM-experiment using COREsBeam alignment

control

Technical details:

3fm-PDH-Lock:demodulate at 3rd harmonicinsensitive to residual AMOffset compensation:Measure and compensate effectsof residual AM, residual etalons,mixer offsets, electrical offsets, ...Active beam pointing:Stabilize incoupling, compensate for cryo movements

Typical measurement - raw dataFeb. 05, 2002Red points: 2 min averagesoff-lock periods removed

Freq

uenc

y de

viat

ion

[Hz]

3 days

100 Hz

Time [days]

Data analysis – single measurement

Data analysis – complete data

Standard Model Extension (SME)

Analysis within SME

Future prospects

New, improved cryostat

Turntable, optimized rotation

Crossed monolithic COREs

Rotating CryostatPVLAS vacuum birefringence experiment

Fiber coupled resonators

Future Prospects- In Space -

OPTIS

Mission study funded by

Heinrich-Heine-Univ.

Universität Düsseldorf

• C. Lämmerzahl

• S. Schiller

ZARM, Univ. Bremen

• H. Dittus

Humboldt-Univ. Berlin

(formerly Univ. Konstanz)

• A. Peters

Satellite-based tests of Special and General Relativity

Mission Idea

• Michelson-Morley

• Kennedy-Thorndike• Gravitational redshift

U2(r)

U1(r)

v1

v2

fs Comb

Summary and Outlook

Improved MM-experiment(3 orders of magnitude)

Improved KT-experiment(1 order of magnitude)

Other fundamental tests ...

No reason to worry, yet ...

COREs are suitable tools for tests of fundamental physicsMichelson-Morley experiment: 3-fold improvement Standard Model Extension parameters: 100-fold improvement

Space based experiments

The team

Holger Müller, Achim Peters, Oliver Pradl, Claus Braxmaier,Sven Herrmann, and Alexsandro Sunaga

MM-experiment using COREsBeam alignment

control

Setup for measuring stability

Spacecraft and orbit"" MassMass 250 kg250 kg

"" Power Power budget budget 250 W250 W

"High elliptic orbit"Period: 14 h"Inclination 63°"Shadow:

5 months without shadow1 month with periods

"Sun rad. press. 4.4 µN/m2

"Earth albedo rad. press.1.2 µN/m2

GTO

HEO

Apogee motorfor orbit transfer

FEEPs:∆F = ± 0.1 µNFmax = 100 µN

+ Reference sensorδa=10-14 m/(s2·# Hz)

In(Cs) Reservoir

ONERA

Cold gas thrusterfor coarse attitude control

Analysis within SME

Sapphire COREs