nsf vision in gravitational physics · nsf vision in gravitational physics • program overview •...

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NSF Vision in Gravitational Physics

• Program Overview• LIGO• Testing GR and searching for new physics: the Gravitational Experiments Program• Comments and questions for the future

Beverly K. BergerProgram Director, Gravitational Physics

Fundamental Physics Research in Space 21–24 May 2006

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LIGO Livingston

LIGO

LIGO Hanford

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—on the verge of gravitational wave astronomy

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Gravitational Wave Research

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Frequency [Hz]

H1: 15 Mpc, Predicted: 17.8, May 14 2006 00:01:52 UTCDARMMICHPRCOscillatorOpt icalLeversWFSOSEMSeismicETMITMBSSusThermIntThermShotDarkIntensityFrequencyTotalSRD

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NoiseDesignPredicted

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5Frequency [Hz]

L1: 14.8 Mpc, Predicted: 14.8, May 21 2006 18:51:23 UTCDARM

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MICHPRCOscillatorOpticalLeversWFSOSEMSeismicETMITMBSSusThermIntThermShotDarkIntensityFrequencyTotalSRD

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NoiseDesignPredicted

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LIGO Scientific Collaboration

Gravitational Wave Research

Scientific Results from LIGO

Known pulsar upper limits

Stochastic background UL

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Fundamental Physicsfrom LIGO

• Directly verify that gravitational waves exist.• Test that these waves propagate at the same speed as light, and that the graviton has zero rest mass.• Test the prediction of gravitational wave tensor polarization.• Confirm that black holes do exist (smoking gun), and test predictions for gravitational waves from colliding black holes. This will be the most stringent test ever of Einstein's general relativity theory.

LIGO can test GR predictions in strong field, dynamical regime:

Advanced LIGO

• Advanced LIGO is in the FY 2007 President’s Budget Request for an FY 2008 funding start.

• Use existing beam tubes and vacuum chambers.

• Upgrade optics, laser, suspensions, seismic isolation.

Advanced LIGO

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Gravitational Wave Source Simulations: Waveforms for LIGO (and LISA) data analysis are now within reach.

Recent Breakthroughs in Numerical Relativity

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Gravitational Experiments

• Inverse square law violation.

• Equivalence principle violation.

Searching for new physics.

• Ground-based astronomical tests of GR.

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Gravitational Experiments

Kapitulnik, preprint

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Gravitational Experiments

http://physicsweb.org/articles/world/18/4/6/1/PWgra4%5F04%2D05

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Gravitational Experiments

Lunar laser ranging to test GR to mm precision. Unique periodicities of GRtest effects should allow identification.

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Gravitational Experiments

Early detection of reflected light for LLR.

Comments & Questions for

Gravitational Experiments

• Broader impacts of Gravitational Experiments Program: potential for new physics, precision measurement technology development, student training

• What are the priorities? Smallest distance scale? Most interesting techniques? Potential for follow-on in space?

• Are there priorities? Speculations from theory?