Final Thoughts and Highlights Barry C. Barish Caltech Amaldi-6 Okinawa 24-June -05

Final Thoughts and Highlights

Barry C. BarishCaltech

Amaldi-6Okinawa

24-June -05

LISA

http://top.html/

24-June-05 Amaldi-6 - Barish 2

Towards Detection of Gravitational Waves

From LISA Concept Demonstrations Mission

From Bars Bars with Increased Bandwidth Spheres

From Interferometers Advanced Interferometers Next Generation (QND) Detectors

From 8 Mpc (NN inspiral) 200 Mpc and then beyond

From Upper Limits Searches Detections

From Generic Searches Searches with Specified Waveforms

From Single Detectors Global Networks


Gravitational Waves in Space

LISA

Three spacecraft, each with a Y-shaped payload, form an equilateral triangle with sides 5 million km in length.


LISA


LISA


LISA


Total number of detatched binaries 208736473

Total number of interacting binaries 34291253

Distribution of WD binaries (Nelemans et al)

WD-WD, WD-NS, NS-NS binaries with GW frequency within LISA band are observed.

These sources are GUARANTEED

Krolak


Data Analysis Issues

Stochastic signal Isolated signals

Interacting signals

Long wavelength regime Short wavelength regime

TDI

LISA motion; long observation times; network of detectors

Krolak


LISA


LISA

The diagram shows the sensitivity bands for LISA and LIGO


DECIGO Bridges the Gap

10-

18

10-

24

10-

22

10-

20

10-

4

104

102

100

10-

2Frequency [Hz]

Str

ain

[H

z-1

/2]

LISA

DECIGO

Terrestrial Detectors (e.g. LCGT)

The Japanese Space Gravitational Wave Antenna - DECIGODeci-hertz Interferometer Gravitational Wave Observatory


Sensitivity of DECIGO

Force noise= 1/100 of LISA’s

10–4 10–3 10–2 10–1 100 101 102 10310–25

10–24

10–23

10–22

10–21

10–20

10–19

10–18

Frequency [Hz]

Str

ain

[

1/H

z1/2]

LCGT

LISA

DECIGO(LISA type, 5x104km)

DECIGO(FP type, 1000km)

Laser: 10W, 532nmMass: 100kgMirror: 1m dia.


ExplorerSwitzerland

Allegro USA

SchenbergBrazil

MiniGrailThe Netherlands

NiobeAustralia

Nautilus, italy

Auriga, ItalyResonant Bar Detectors



“spheres”• omnidirectionality: decode the excitation of the 5 quadrupolar modes to get uniform sky coverage & find direction of propagation • cross section: larger as the volume fill-up factor in respect to bars

MiniGRAIL (Leiden-Rome) just started operation

Talks of Annette de Waard and Luciano

Gottardi

Schenberg (Brasil) coming to

sensitive in a few kHz-wide freq band !!!

GW signals addback action noises subtract

read-out with non-resonating transducers the differential deformations at frequencies between the lowest quadrupolar modes

DUAL: two nested resonant massesCerdonio et al PRL (2001), Bryant et al PRD (2003), Bonaldi et al PRD (2003)

talk by Michele Bignotto


sensitivities in the 2006 - 2012 prospective

Bar Network


International Gravitational Event Collaboration (IGEC)

ALLEGRO,AURIGA,EXPLORER, NAUTILUS, and NIOBE 1997-2000.

The search for burst waves at resonant frequency ~ 900 Hz.

The detectors nearly parallel to maximize coincident sensitivity.

Candidate events at SNR > 3-5 (~ background events 100/day)

Data exchanged: peak amplitude, time of event and uncertainties.

Threshold equivalent to ~0.1 M⊙ converted into a gravitational wave millisecond burst at a distance of 10 kpc.

The accidental coincidence rate over 1 sec interval (e.g. bandwidth of 1 Hz) was ~ few/week two-fold and ~few/century three-fold.

Time resolution not sufficient to resolve incident wave direction, no directional search has been applied.

No evidence for grav wave bursts was found.


rate[y –1]

search threshold h

1.E+00

1.E+01

1.E+02

1.E+03

1E-18 1E-17 1E-16

IGEC

h ~ 2 10-18 E ~ 0.02 M⊙ converted @ 10 kpc

Upper Limit on the Rate of gravitational waves bursts from the GALACTIC CENTER

random arrival times and amplitude search threshold h

The Area above the blue curve is excluded with a coverage > 90%

[P. Astone, et al. Phys. Rev. D68 (2003) 022001]

IGEC coincidence search

Final results


During 2001 EXPLORER and NAUTILUS were the only two operating resonant detectors, with the best ever reached sensitivity.An algorithm based on energy compatibility of the event was applied to reduce the “background”

EXPLORER-NAUTILUS 2001

Sidereal hours

Nu

mb

er o

f ev

ents

ROG Coll.: CQG 19, 5449 (2002)L.S.Finn: CQG 20, L37 (2003)P.Astone, G.D’Agostini, S.D’Antonio: CQG Proc. Of GWDAW 2002, gr-qc/0304096E. Coccia ROG Coll.:CQG Proc. Of GWDAW 2002ROG Coll.: gr-qc/0304004

New data needed

Excess ???Direction of Galactic Disc


ROG S 03

ROG S 01 suggestion

- crewless operation - data validated by cosmic ray effect - new upper limit with bars, no significant coincidence excess nor sidereal effect.

EXPLORER NAUTILUS Science Run 03


IGEC-2Expected Performance

Triple coincidences: 106 time shifts, no accidentals, 9.3 days false alarm rate < 10-4 / yr for H>1.4 10-21/Hz

Double coincidences:lower false alarm rates than for IGEC-1

rate[year –1]

search threshold

dashed region excluded with probability

> 90%

My best guess on the achievable upper limit improvement by IGEC-2

WARNING:incomplete data set !

1 month

1 year

IGEC-1 upper limit


InterferometerDetectors

LIGO Louisiana 4000mTAMA Japan

300m

Virgo Italy 3000m

GEO Germany 600mAIGO Australia

future

LIGO Washington 2000m & 4000m


TAMA

Kanda


TAMA

Kanda


S4 Sensitivity


Noise Progression of the Louisiana Interferometer


Results for Neutron Star Binaries

Event Candidates» 142 event candidates found

in the data» Loudest candidates

eliminated in follow up investigation…

» Other candidates consistent with background of analysis pipeline

Upper limit set on the rate of BNS coalescences

R90 = 47 / year / MWEG


Results for Primordial Black Hole Binaries

Same analysis pipeline Event rate consistent with

background of analysis pipeline

Upper limit set on the rate of PBHB coalescences

R90 = 63 / year / MWEG


-16 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8

-14

-12

-10

-8

-6

-4

-2

0

Log ( f [Hz])

Lo

g(

0h 1

002 )

f ~ H0 - one oscillation in the

lifetime of the universe

f ~ 1/Plank scale – red shifted from the Plank era to the present time

-18 10

Laser Interferometer Space Antenna - LISA

Inflation

Slow-roll

Cosmic strings

Pre-big bang model

EW or SUSY Phase transition

Cyclic model

CMB

Pulsar Nucleosynthesis

LIGO band

Stochastic BackgroundPredictions and Experimental Limits

LIGO S1, 2 wk data Ω0h100

2 < 23 PRD 69(2004)122004

(H2-L1)

Advanced LIGO, 1 yr data Expected Ω0h100

2 < 7x10-10

(H1-L1)

LIGO S3, 2 month data Ω0h100

2 < 4.4x10-4 (H1-L1) presented here Initial LIGO, 1 yr data Expected Ω0h100

2 < 2x10-6

(H1-L1)


Conclusions Sensitivity toward gravitational wave detection is improving

on many fronts and this will continue well into the future

New upper limits are being set for the major sources -- binary inspirals, periodic sources, burst sources and stochastic background.

Data exchange and joint data analysis between detector groups is improving our ability to make detections

Many exciting future projects and upgrades are planned or getting underway.

Hopefully, detections will be made soon !! Maybe by Amaldi-7??


THANKSAmaldi-6

Organizers!!!

See at Amaldi-7 Sydney

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Final Thoughts and Highlights Barry C. Barish Caltech Amaldi-6 Okinawa 24-June -05

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