Detecting Einstein’s Elusive Waves

Opening a New Window to the Universe

LIGO-India: An Indo-US joint mega-project concept proposal

IndIGO Consortium(Indian Initiative in Gravitational-wave Observations)

Version: pI_v2 Jun 20, 2011 : TSwww.gw-indigo.org

Beauty & Precision

Einstein’s Gravity predicts • Matter in motion Space-time ripples

fluctuations in space-time curvature that propagate as waves

Gravitational waves (GW)

• In GR, as in EM, GW travel at the speed of light (i.e., mass-less) , are transverse and have two states of

polarization.

• The major qualitatively unique prediction beyond Newton’s gravity

Begs direct verification !!!

A Century of Waiting• Almost 100 years since Einstein predicted GW but

no direct experimental confirmation (a la Hertz for Maxwell EM theory)

• Two Fundamental Difference between GR and EM- Weakness of Gravitation relative to EM (10^-39)-Spin two nature of Gravitation vs Spin one of EM that forbids dipole

radiation in GR

• Low efficiency for conversion of mechanical energy to GW. Feeble effects of GW on a Detector

• GW Hertz experiment ruled out. Only astrophysical systems involving huge masses and accelerating very strongly are potential detectable sources of GW signals.

Pulsar companion

GW from Binary Neutron stars

• leads to loss of orbital energy

• period speeds up 14 sec from 1975-94

• measured to ~50 msec accuracy

• deviation grows quadratically with time

Binary pulsar systems emit gravitational waves

Hulse and TaylorResults for PSR1913+16

Indirect evidence for Gravity wavesIndirect evidence for Gravity waves

Nobel prizein 1993 !!!

Effect of GW on a ring of test massesEffect of GW on a ring of test masses

Interferometer mirrors as test massesInterferometer mirrors as test masses

Courtesy: Stan Whitcomb

end test mass

beam splittersignal

LIGO Optical Configuration

Laser

MichelsonInterferometer

MichelsonInterferometer

input test massLight is “recycled” about 50 times

Power Recycled

with Fabry-Perot Arm Cavities

Light bounces back and forth along arms about 100 times

Detecting GW with Laser Interferometer

Difference in distance of Paths Interference of laser light at the detector (Photodiode)

LIGO and Virgo TODAYMilestone: Decades-old plans to build and operate large interferometric GW detectors now realized at several locations worldwideExperimental prowess: LIGO, VIRGO operating at predicted sensitivity!!!!

Pre-dawn GW astronomy : Unprecedented sensitivity already allows• Upper Limits on GW from a variety of Astrophysical sources. Refining theoretical modelling• Improve on Spin down of Crab, Vela pulsars, • Exptally surpass Big Bang nucleosynthesis bound on Stochastic GW..

IndIGO - ACIGA meeting 10

Laser Interferometer Gravitational-wave Observatory (LIGO)

Courtesy;: Stan Whitcomb11

Astrophysical Sources for Terrestrial GW Detectors

• Compact binary inspiral: “chirps”

– NS-NS, NS-BH, BH-BH

• Supernovas or GRBs: “bursts”

– GW signals observed in coincidence with EM or neutrino detectors

• Pulsars in our galaxy: “periodic waves”

– Rapidly rotating neutron stars

– Modes of NS vibration

• Cosmological: “stochastic background” ?

– Probe back to the Planck time (10-43 s)

– Probe phase transitions : window to force unification

– Cosmological distribution of Primordial black holes

vit

GWIC Roadmap Document

Gravitational wave Astronomy :

Synergy with other major Astronomy projects

• SKA : Pulsars timing and GW background, GW from Pulsars ,…( RADIO: Square Kilometer array)• CMB : GW from inflation, cosmic phase transitions, dark energy ….(Cosmic Microwave Background : WMAP, Planck, CMBPOl, QUaD,…)• X-ray satellite (AstroSat) : Spacetime near Black Holes, NS, …. • Gamma ray observatory: GRB triggers from GW(FermiLAT, GLAST,….)• Thirty Meter Telescope: Resolving multiple AGNs, optical follow-up, …• INO: cross correlate neutrino signals from SN event• LSST: Astro-transients with GW triggers, Cosmic distribution of dark matter , Dark energy• •

Advanced LIGO•Take advantage of new technologies and on-going R&D

>> Active anti-seismic system operating to lower frequencies:(Stanford, LIGO)

>> Lower thermal noise suspensions and optics : (GEO )

>> Higher laser power 10 W 180 W (Hannover group, Germany)

>> More sensitive and more flexible optical configuration: Signal recycling

• Design: 1999 – 2010 : 10 years of high end R & D internationally.

• Construction: Start 2008; Installation 2011; Completion 2015

Era of Advanced LIGO detectors: 2015

10x sensitivity10x reach

1000 volume>> 1000 event rate

(reach beyond

nearest super-clusters)

A Day of Advanced LIGO Observation >> A year of Initial LIGO

Expected Annual Coalescence Event RatesDetector Generation

NS-NS NS-BH BH-BH

Initial LIGO(2002 -2006) 0.02 0.0006 0.0009

Enhanced LIGO(2X Sensitivity)(2009-2010)

0.1 0.04 0.07

Advanced LIGO(10X sensitivity)(2014 - …)

40 10. 20.0

In a 95% confidence interval, rates uncertain by 3 orders of magnitudeNS-NS (0.4 - 400); NS-BH (0.2 - 300) ; BH-BH (2 - 4000) yr^-1

Based on Extrapolations from observed Binary Pulsars, Stellar birth rateestimates, Population Synthesis models. Rates quoted below are mean of the distribution.

Using GWs to Learn about the Source: an Example

• Distance from the earth r• Masses of the two bodies• Orbital eccentricity e and orbital inclination i

Can determine

Over two decades, RRI involved in computation of inspiral waveforms for compact binaries & their implications andIUCAA in its Data Analysis Aspects.

17

From the GWIC Strategic Roadmap for GW Science with thirty year horizon (2007)

• … the first priority for ground-based gravitational wave detector development is to expand the network, adding further detectors with appropriately chosen intercontinental baselines and orientations to maximize the ability to extract source information. ….Possibilities for a detector in India (IndIGO) are being studied..

GW Astronomy with Intl. Network of GW ObservatoriesGW Astronomy with Intl. Network of GW Observatories

LIGO-LLO: 4km

LIGO-LHO: 2km+ 4kmGEO: 0.6km VIRGO: 3km

LCGT 3 kmTAMA/CLIO

LIGO-Australia?

1. Detection confidence 2. Duty cycle 3. Source direction 4. Polarization info.

LIGO-India ?

Scientific PayoffsAdvanced GW network sensitivity needed to observe

GW signals at monthly or even weekly rates.• Direct detection of GW probes strong field regime of gravitation Information about systems in which strong-field and time dependent gravitation dominates, an untested regime including non-linear self-interactions

• GW detectors will uncover NEW aspects of the physics Sources at extreme physical conditions (eg., super nuclear density physics), relativistic motions, extreme high density, temperature and magnetic fields.

• GW signals propagate un-attenuated weak but clean signal from cores of astrophysical event where EM signal is screened by ionized matter.

• Wide range of frequencies Sensitivity over a range of astrophysical scales

To capitalize one needs a global array of GW antennas separated by continental distances to pinpoint sources in the sky and extract all the source information encoded in the GW signals

LIGO-India: … the opportunityStrategic Geographical relocation: science gainSource localization error

Original plan2 +1 LIGO USA+ Virgo

LIGO-India plan1+1 LIGO USA+ Virgo+ LIGO India

LIGO-Aus plan1+1 LIGO USA+ Virgo+ LIGO Aus

LIGO-India: … the opportunity

Polarization info

Homogeneity of Sky coverage

Courtesy: B. Schutz

Strategic Geographical relocation: science gain

LIGO-India: … the opportunity

Sky coverage: Synthesized Network beam(antenna power)

Courtesy: B. Schutz

Strategic Geographical relocation: science gain

LIGO-India: … the opportunity

Sky coverage: ‘reach’ /sensitivity in different directions

Courtesy: B. Schutz

Strategic Geographical relocation: science gain

Indian Gravitational wave legacyTwo decades of Indian contribution to the international effort for

detecting GW on two significant fronts :• Seminal contributions to source modeling at RRI [Bala Iyer] and to GW data

analysis at IUCAA [Sanjeev Dhurandhar] which has been internationally recognized

• RRI: Indo-French collaboration for two decades to compute high accuracy waveforms for in-spiraling compact binaries from which the GW templates used in LIGO and Virgo are constructed.

• IUCAA: Designing efficient data analysis algorithms involving advanced mathematical concepts.

• Notable contributions include the search for binary in-spirals, hierarchical methods, coherent search with a network of detectors and the radiometric search for stochastic gravitational waves.

• IUCAA has collaborated with most international GW detector groups and has been a member of the LIGO Scientific Collaboration.

• At IUCAA, Tarun Souradeep with expertise in CMB data and Planck has worked to create a bridge between CMB and GW data analysis challenges.

Indian Gravitational wave strengths• Very good students and post-docs produced from these activities. * Leaders in GW research abroad [Sathyaprakash, Bose, Mohanty] (3)

*Recently returned to faculty positions at premier Indian institutions (6) [Gopakumar, Archana Pai, Rajesh Nayak, Anand Sengupta, K.G. Arun, Sanjit Mitra, P. Ajith?]

– Gopakumar (Jena -->TIFR) and Arun (Virgo -->CMI) : PN modeling, dynamics of CB, Ap and cosmological implications of parameter estimation

– Rajesh Nayak (UTB IISER K) , Archana Pai (AEI IISER T), Anand Sengupta (LIGO, Caltech Delhi), Sanjit Mitra (JPL IUCAA ): Extensive experience on single and multi-detector detection, hierarchical techniques, noise characterisation schemes, veto techniques for GW transients, bursts, continuous and stochastic sources, radiometric methods, …

– P. Ajith (Caltech, LIGO/TAPIR ? ) ……– Sukanta Bose (Faculty UW, USA ?)

Strong Indian presences in GW Astronomy with Global detector network Strong Indian presences in GW Astronomy with Global detector network broad broad international collaboration is the norm international collaboration is the norm relatively easy to get people back. relatively easy to get people back.

• Close interactions with Rana Adhikari (Caltech), B.S. Sathyaprakash (Cardiff), Sukanta Bose ( WU, Pullman), Soumya Mohanty (UTB), Badri Krishnan ( AEI) …

• Very supportive Intl community reflected in Intl Advisory committee of IndIGO

High precision and Large experiment in India• C.S. Unnikrishnan (TIFR) : involved in high precision experiments and tests

– Test gravitation using most sensitive torsional balances and optical sensors.– Techniques related to precision laser spectroscopy, electronic locking, stabilization.– Ex students from this activity G.Rajalakshmi (TIFR, 3m prototype) Suresh Doravari (Caltech 40m)

• Groups at BARC and RRCAT : involved in LHC – providing a variety of components and subsystems like precision magnet positioning stand jacks,

superconducting correcting magnets, quench heater protection supplies and skilled manpower support for magnetic tests and measurement and help in commissioning LHC subsystems.

• S.K. Shukla at RRCAT on INDUS: UHV experience. • S.B. Bhatt and Ajai Kumar at IPR on Aditya: UHV experience. • A.S. Raja Rao (ex RRCAT) : consultant on UHV• Sendhil Raja (RRCAT) :

– Optical system design– laser based instrumentation, optical metrology– Large aperture optics, diffractive optics, micro-optic system design.

• Anil Prabhakar IITM and Pradeep Kumar IITK (EE dept s)– Photonics, Fiber optics and communications– Characterization and testing of optical components and instruments for use in India..

• Rijuparna Chakraborty (Observatoire de la Cote d'Azur)..Adaptive Optics.. – Under consideration for postdoc in LIGO or Virgo….

Multi-Institutional,Multi-disciplinary Consortium(2009)

1. CMI, Chennai2. Delhi University3. IISER Kolkata4. IISER Trivandrum5. IIT Madras (EE)6. IIT Kanpur (EE)7. IUCAA8. RRCAT9. TIFR

• RRI• IPR, Bhatt• Jamia Milia Islamia• Tezpur Univ

The IndIGO Consortium

Data Analysis & Theory

1. Sanjeev Dhurandhar IUCAA2. Bala Iyer RRI3. Tarun Souradeep IUCAA4. Anand Sengupta Delhi University 5. Archana Pai IISER, Thiruvananthapuram6. Sanjit Mitra JPL , IUCAA7. K G Arun Chennai Math. Inst., Chennai8. Rajesh Nayak IISER, Kolkata9. A. Gopakumar TIFR, Mumbai 10. T R Seshadri Delhi University 11. Patrick Dasgupta Delhi University12. Sanjay Jhingan Jamila Milia Islamia, Delhi13. L. Sriramkumar, Phys., IIT M14. Bhim P. Sarma Tezpur Univ . 15. Sanjay Sahay BITS, Goa16. P Ajith Caltech , USA17. Sukanta Bose, Wash. U., USA18. B. S. Sathyaprakash Cardiff University, UK19. Soumya Mohanty UTB, Brownsville , USA20. Badri Krishnan Max Planck AEI, Germany

Instrumentation & Experiment

1. C. S. Unnikrishnan TIFR, Mumbai2. G Rajalakshmi TIFR, Mumbai3. P.K. Gupta RRCAT, Indore 4. Sendhil Raja RRCAT, Indore5. S.K. Shukla RRCAT, Indore6. Raja Rao ex RRCAT, Consultant 7. Anil Prabhakar, EE, IIT M8. Pradeep Kumar, EE, IIT K9. Ajai Kumar IPR, Bhatt10. S.K. Bhatt IPR, Bhatt 11. Ranjan Gupta IUCAA, Pune12. Bhal Chandra Joshi NCRA, Pune13. Rijuparna Chakraborty, Cote d’Azur, Grasse14. Rana Adhikari Caltech, USA 15. Suresh Doravari Caltech, USA 16. Biplab Bhawal (ex LIGO)

IndIGO Council1. Bala Iyer ( Chair) RRI,

Bangalore 2. Sanjeev Dhurandhar (Science) IUCAA, Pune 3. C. S. Unnikrishnan (Experiment) TIFR, Mumbai4. Tarun Souradeep (Spokesperson) IUCAA, Pune

23 July 2011Dear Bala:

I am writing to invite you to attend the next meeting of the Gravitational Wave International Committee (GWIC) to present the GWIC membership to present the GWIC membership application for IndIGO.application for IndIGO. This in-person meeting will give you the opportunity to interact with the members of GWIC and to answer their questions about the status and plans for IndIGO. Jim Hough (the GWIC Chair) and I have reviewed your application and believe that you have made a strong case for you have made a strong case for membership……membership……

IndIGO: the goals & roles• Provide a common umbrella to initiate and expand GW related experimental activity

and training new manpower – 3m prototype detector in TIFR (funded) - Unnikrishnan– Laser expt. RRCAT, IIT M, IIT K - Sendhil Raja, Anil Prabhakar, Pradeep Kumar– Ultra High Vacuum & controls at RRCAT, IPR, BARC, ISRO, …. Shukla, Raja Rao, Bhatt,– UG summer internship at National & International GW labs & observatories.– Postgraduate IndIGO schools, specialized courses,…

• Consolidated IndIGO membership of LIGO Scientific Collaboration in Advanced LIGO Proposal to create a Tier-2 data centre for LIGO Scientific Collaboration in IUCAA IUSSTF Indo-US joint Centre at IUCAA with Caltech (funded)

• Major experimental science initiative in GW astronomy Earlier Plan: Partner in LIGO-Australia (a diminishing possibility)

– Advanced LIGO hardware for 1 detector to be shipped to Australia at the Gingin site, near Perth. NSF approval– Australia and International partners find funds (equiv to half the detector cost ~$140M and 10 year running cost ~$60M) within a year.– Indian partnership at 15% of Australian cost with full data rights.

Today: LIGO-India (Letter from LIGO Labs)– Advanced LIGO hardware for 1 detector to be shipped to India.– India provides suitable site and infrastructure to house the GW observatory– Site, two 4km arm length high vacuum tubes in L configuration– Indian cost ~ Rs 1000Cr

The Science & technology benefit of LIGO-India is transformational

IndIGO 3m Prototype Detector

Funded by TIFR Mumbai on compus (2010)PI: C. S. Unnikrishnan (Cost ~ INR 2.5 crore)

Vacuum tanksDetector

Laser table

Vibration isolationschematic

All mirros and beamsplitters are suspended as in the diagram on right

3.2 meters

0.8 mF-P cavityPower recycling

Sensing &Control

60 cm

180 cm

Mirror

Dear Prof. Kasturirangan, 1 June 2011

In its road-map with a thirty year horizon, the Gravitational Wave International Committee (a working unit of the International Union of Pure and Applied Physics, IUPAP) has identified the expansion of the global network of gravitational wave interferometer observatories as a high priority for maximizing the scientific potential of gravitational wave observations. We are writing to you to put forward a concept proposal on behalf of LIGO Laboratory (USA) and the IndIGO a concept proposal on behalf of LIGO Laboratory (USA) and the IndIGO Consortium, for a Joint Partnership venture to set up an Advanced gravitational wave detector Consortium, for a Joint Partnership venture to set up an Advanced gravitational wave detector at a suitable Indian site. at a suitable Indian site. In what follows this project is referred to as LIGO-India. The key idea The key idea is to utilize the high technology instrument components already fabricated for one of the three is to utilize the high technology instrument components already fabricated for one of the three Advanced LIGO interferometers in an infrastructure provided by India that matches that of the Advanced LIGO interferometers in an infrastructure provided by India that matches that of the US Advanced LIGO observatories.US Advanced LIGO observatories.

LIGO-India could be operational early in the lifetime of the advanced versions of gravitational wave operational early in the lifetime of the advanced versions of gravitational wave observatoriesobservatories now being installed the US (LIGO) and in Europe (Virgo and GEO) and would be of great value not only to the gravitational wave community, but to broader physics and astronomy research by launching an era of gravitational wave astronomy, including, the fundamental first direct detection of gravitational waves. As the southernmost member observatory of the global array of gravitational wave detectors, India would be unique among nations leading the scientific exploration India would be unique among nations leading the scientific exploration of this new window on the universeof this new window on the universe. The present proposal promises to achieve this at a fraction of a fraction of the total cost of independently establishing a fully-equipped and advanced observatory. the total cost of independently establishing a fully-equipped and advanced observatory. It also offers technology that was developed over two decades of highly challenging global R&D effort that preceded the success of Initial LIGO gravitational wave detectors and the design of their advanced version.

LIGO-India from LIGO LIGO-India from LIGO

LIGO-India: Why is it a good idea?… for the World

• Strategic geographical relocation for GW astronomy– Increased event rates (x4) by coherent analysis – Improved duty cycle– Detection confidence– Improved Sky Coverage– Improved Location of Sources required for multi-messenger astronomy– Determine the two polarizations of GW

• Potentially large science community in future– Indian demographics: youth dominated – need challenges– excellent UG education system already produces large number of

trained in India find frontline research opportunity at home.

• Large data analysis trained manpower and facilities exist (and being created).

LIGO-India: Why is it a good idea? …for India

• Have a 20 year legacy and wide recognition in the Intl. GW community with seminal contributions to Source modeling (RRI)& Data Analysis (IUCAA). High precision measurements (TIFR), Participation in LHC (RRCAT)Would not make it to the GWIC report, otherwise!

– LIGO/ACIGA/EGO strong interest in fostering Indian community– GWIC invitation to IndIGO join as member (July 2011)

• Provides an exciting challenge at an International forefront of experimental science. Can tap and siphon back the extremely good UG students trained in India. (Sole cause of `brain drain’).– 1st yr summer intern 2010 MIT for PhD– Indian experimental scientist Postdoc at LIGO training for Adv. LIGO subsystem

• Indian experimental expertise related to GW observatories will thrive and attain high levels due to LIGO-India. – Sendhil Raja, RRCAT, Anil Prabhakar, EE, IIT Madras, Pradeep Kumar, EE, IITK

Photonics– Vacuum expertise with RRCAT (S.K. Shukla, A.S. Raja Rao) , IPR (S.K. Bhatt, Ajai Kumar)• Jump start direct participation in GW observations/astronomy going beyond analysis methodology & theoretical prediction --- to full fledged

participation in experiment, data acquisition, analysis and astronomy results.

Science Payoffs

New Astronomy, New Astrophysics, New Cosmology, New Physics

” A New Window ushers a New Era of Exploration in Physics & Astronomy”

– Testing Einstein’s GR in strong and time-varying fields– Testing Black Hole phenomena– Understanding nuclear matter by Neutron star EOS– Neutron star coalescence events– Understanding most energetic cosmic events ..Supernovae, Gamma-ray bursts,

LMXB’s, Magnetars– New cosmology..SMBHB’s as standard sirens..EOS of Dark Energy– Phase transition related to fundamental unification of forces– Multi-messenger astronomy– The Unexpected !!!!!

Technology Payoffs• Lasers and optics..Purest laser light..Low phase noise, excellent

beam quality, high single frequency power• Applications in precision metrology, medicine, micro-machining• Coherent laser radar and strain sensors for earthquake prediction

and other precision metrology• Surface accuracy of mirrors 100 times better than telescope

mirrors..Ultra-high reflective coatings : New technology for other fields

• Vibration Isolation and suspension..Applications for mineral prospecting

• Squeezing and challenging “quantum limits” in measurements.• Ultra-high vacuum system 10^-9 torr (1picomHg). Beyond best in

the region. The largest UHV system will provide industry a challenge and experience.

• Computation Challenges: Cloud computing, Grid computing, new hardware and software tools for computational innovation.

Rewards and spinoffs

Detection of GW is the epitome of breakthrough science!!!

• LIGO-India India could become a partner in international science of Nobel Prize significance

• GW detection is an instrument technology intensive field pushing frontiers simultaneously in a number of fields like lasers and photonics. Impact allied areas and smart industries.

• The imperative need to work closely with industry and other end users will lead to spinoffs as GW scientists further develop optical sensor technology.

• Presence of LIGO-India will lead to pushing technologies and greater innovation in the future.

• Increase number of research groups performing at world class levels and produce skilled researchers.

… rewards and spinoffs

• LIGO-India will raise public/citizen profile of science since it will be making ongoing discoveries fascinating the young. GR, BH, EU and Einstein have a special attraction and a pioneering facility in India participating in important discoveries will provide science & technology role models

with high visibility and media interest.

• LIGO has a strong outreach tradition and LIGO-India will provide a platform to increase it and synergetically benefit.

• Increase international collaborations in Indian research & establishing Science Leadership in the Asia-Pacific region.

• For once, perfect time to a launch into a promising field (GW astronomy) with high end technological spinoffs, well before it has obviously blossomed.

• Once in a generation opportunity to host an Unique, path

defining, International Experiment in India .

END

•Thank you !!!Thank you !!!

Committees: National Steering Committee:Kailash Rustagi (IIT, Mumbai) [Chair]Bala Iyer (RRI) [Coordinator]Sanjeev Dhurandhar (IUCAA) [Co-Coordinator]D.D. Bhawalkar (Quantalase, Indore)[Advisor]P.K. Kaw (IPR)Ajit Kembhavi (IUCAA) P.D. Gupta (RRCAT)J.V. Narlikar (IUCAA)G. Srinivasan

International Advisory Committee

Abhay Ashtekar (Penn SU)[ Chair]Rana Adhikari (LIGO, Caltech, USA)David Blair (ACIGA &UWA, Australia)Adalberto Giazotto (Virgo, Italy)P.D. Gupta (Director, RRCAT, India)James Hough (GEO ; Glasgow, UK)[GWIC Chair]Kazuaki Kuroda (LCGT, Japan)Harald Lueck (GEO, Germany)Nary Man (Virgo, France)Jay Marx (LIGO, Director, USA)David McClelland (ACIGA&ANU, Australia)Jesper Munch (Chair, ACIGA, Australia)B.S. Sathyaprakash (GEO, Cardiff Univ, UK)Bernard F. Schutz (GEO, Director AEI, Germany)Jean-Yves Vinet (Virgo, France)Stan Whitcomb (LIGO, Caltech, USA)

IndIGO Advisory Structure

Program Management Committee:C S Unnikrishnan (TIFR, Mumbai), [Chair]Bala R Iyer (RRI, Bangalore), [Coordinator]Sanjeev Dhurandhar (IUCAA, Pune) [Co-cordinator]Tarun Souradeep (IUCAA, Pune)Bhal Chandra Joshi (NCRA, Pune)P Sreekumar (ISAC, Bangalore)P K Gupta (RRCAT, Indore)S K Shukla (RRCAT, Indore)Sendhil Raja (RRCAT, Indore)]

Network HHLV HILV AHLV

Mean horizon distance

1.74 1.57 1.69

Detection Volume

8.98 8.77 8.93

Volume Filling factor

41.00% 54.00% 44.00%

Triple Detection Rate(80%)

4.86 5.95 6.06

Triple Detection Rate(95%)

7.81 8.13 8.28

Sky Coverage: 81%

47.30% 79.00% 53.50%

Directional Precision

0.66 2.02 3.01

Strategic Geographical relocation: science gain

Special Relativity (SR) replaced Absolute space and Absolute Time by flat 4-dimensional space-time (the normal three dimensions of space, plus a fourth dimension of time).

In 1916, Albert Einstein published his famous Theory of General Relativity, his theory of gravitation consistent with SR, where gravity manifests as a curved 4-diml space-time

Theory describes how space-time is affected by mass and also how energy, momentum and stresses affects space-time.

Matter tells space-time how to curve, and

Space-time tells matter how to move.

Space Time as a fabric

Space Time as a fabric

Earth follows a “straight path” in the curved space-time caused by sun’s mass !!!

What happens when

matter is in motion?

Detecting GW with Laser Interferometer

Difference in distance of Path A & B Interference of laser light at the detector (Photodiode)

Path A

Path B

AB

Principle behind Detection of GW Principle behind Detection of GW

Indo-Aus.Meeting, Delhi, Feb 2011

Concluding remarks• A century after Einstein’s prediction, we are on the threshold of a new

era of GW astronomy following GW detection. Involved four decades of very innovative and Herculean struggle at the edge of science & technology

• First generation detectors like Initial LIGO and Virgo have achieved design sensitivity Experimental field is mature

Broken new ground in optical sensitivity, pushed technology and proved technique.

• Second generation detectors are starting installation and expected to expand the “Science reach” by factor of 1000

• Cooperative science model: A worldwide network is starting to come on line and the ground work has been laid for operation as a integrated system.

• Low project risk : A compelling Science case with shared science risk, a proven design for India’s share of task (other part : opportunity w/o responsibility)

• National mega-science initiative: Need strong multi-institutional support to bring together capable scientists & technologist in India

• An unique once-in-a-generation opportunity for India. India could play a key role in Intl. Science by hosting LIGO-India.

… Concluding remarks• A GREAT opportunity but a very sharp deadline of 31 Mar 2012. If we cannot act

quickly the possibility will close. Conditions laid out in the Request Doc of LIGO-Lab will need to be ready for LIGO-Lab examination latest by Dec 2011 so that in turn LIGO-Lab can make a case with NSF by Jan 2012.

• Of all the large scientific projects out there, this one is pushing the greatest number of technologies the hardest.

“Every single technology they’re touching they’re pushing, and there’s a lot of different technologies they’re touching.”

(Beverly Berger, National Science Foundation Program director for gravitational physics. )

• One is left speculating if by the centenary of General Relativity in 2015, the first discovery of Gravitational waves would be from a Binary Black Hole system, and Chandrasekhar would be doubly right about

Astronomy being the natural home of general Astronomy being the natural home of general relativity.relativity.

50

Initial LIGO Sensitivity Goal

• Strain sensitivity <3x10-23 1/Hz1/2

at 200 Hz

Sensor Noise» Photon Shot Noise» Residual Gas

Displacement Noise» Seismic motion» Thermal Noise» Radiation Pressure

Astrophysical systems are sources of copious GW emission:

•GW emission efficiency (10% of mass for BH mergers) >> EM radiation via Nuclear fusion (0.05% of mass)

Energy/mass emitted in GW from binary >> EM radiation in the lifetime

• Universe is buzzing with GW signals from cores of astrophysical eventsBursts (SN, GRB), mergers, accretion, stellar cannibalism ,…

• Extremely Weak interaction, hence, has been difficult to detect directly

But also implies GW carry unscreened & uncontaminated signals

GW Astronomy link