IndIGO

Indian Initiative in Gravitational-wave Observations

Detecting Einstein’s Elusive Waves

Opening a New Window to the Universe Inaugurating Gravitational wave Astronomy LIGO-India: An Indo-US joint mega-project concept proposal

Bala Iyer, RRI, Bangalore Chair, IndIGO Consortium Council On behalf of the IndIGO Consortium

www.gw-indigo.org

Version: pI_v3 Jun 22, 2011 : BI

What are Gravitational waves and how best to detect them??

Beauty & Precision

Einstein’s General theory of relativity is considered the most beautiful , as well as, theory of modern physics

.

It has matched

all weak field

experimental tests of Gravitation in the solar system remarkably well

…

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 , are transverse and have two states of polarization.

•

GW are a major qualitatively unique prediction beyond Newton’s gravitation

• Any theory of Gravitation consistent with SR will lead to GW…However, the properties of GW in different theories of gravity could be different …

1975 - Hulse and Taylor Binary Pulsar 1913+16

Companion NS P Pulsar •

Exquisite Lab for Tests of GR beyond static & weak Grav fields

•

High quality Pulsar Timing Data shows that after correcting for ALL known relativistic and astrophysical kinematic effects, the binary system is losing orbital energy

•

Period (measurable to 50ms accuracy) speeds up by 14s from 1975-94 as predicted by Einstein’s GR.

Binary pulsar systems emit gravitational waves

Nobel prize in 1993 !!!

Nobel Prize clinching evidence for Gravitational waves BUT still Indirect evidence….

Astrophysical Sources for Terrestrial GW Detectors

•

Compact binary Coalescence: “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

6

GW cause Oscillatory Tidal distortions on a ring of particles Suspended mirrors of an interferometer act as (freely falling) test masses (in hor pl for f>>f_pend),undergo tidal deformations leading to path differences

h

Strain

 

L

/

L

•Path difference due to tidal distortion  phase difference •

Change in Length manifests as a Change in Transmitted Light

Challenge of GW Detection A century of waiting

•

Two Fundamental Diffs between GR &EM

-

Weakness of Gravitation relative to EM (10^-39) -Massless Spin two nature of Gravitation vs Spin one of EM that forbids dipole radiation in GR

•

A NS-NS Binary in the Virgo cluster (20 Mpc) produces a strain of h ~ 10

–22

– 10

–21

.

•

For a 4 km detector one must effectively measure the miniscule displmnt



L

~ 10

-18

m

• GW detection is about seeing the biggest things that ever happen by measuring the smallest changes that have ever been measured - Harry Collins.

Detecting GW with Laser Interferometer

Power Recycled Michelson Interferometer

LIGO Optical Configuration

end test mass

with Fabry-Perot Arm Cavities

Light bounces back and forth along arms about 100 times Light is “recycled” about 50 times input test mass

Laser

signal beam splitter

Difference in distance of Paths



Interference of laser light at the detector (Photodiode)

Courtesy: Stan Whitcomb

Current Status of World-wide GW detection efforts

Laser Interferometer Gravitational-wave Observatory (LIGO) USA, 4 km

IndIGO - ACIGA meeting 11

Virgo

(Cascina, near Pisa, Italy) French-Italian, 3km

Experimental Milestone

Km-scale interferometric GW detectors LIGO and Virgo achieved their predicted design goals.

Strain sensitivity <3x10 -23 /Sqrt(Hz) at 200 Hz.

Unprecedented sensitivity already allows

•

Upper Limits on GW from a variety of Astrophysical sources.

•

Improve on Spin down of Crab, Vela pulsars..

Less than 2% available energy in Crab emitted as GW

•

Surpass Big Bang nucleosynthesis bound on Stochastic GW..

Pre-dawn GW astronomy

Towards Advanced LIGO & Virgo

Era of Advanced LIGO detectors: 2015

10x sensitivity



10x dist reach



1000 volume



>> 1000X event rate



( reach beyond nearest super clusters ) A Day of Advanced LIGO Observation >> A year of Initial LIGO observation

Mean Expected Annual Coalescence Event Rates

Detector Generation

Initial LIGO (2002 -2006) Advanced LIGO (10X sensitivity) (2014+ - …)

NS-NS

0.02

40

NS-BH

0.0006

10.

BH-BH

0.0009

20.0

In a 95% confidence interval, rates uncertain by 3 orders of magnitude NS-NS (0.4 - 400); NS-BH (0.2 - 300) ; BH-BH (2 - 4000) yr^-1 Based on Extrapolations from observed Binary Pulsars, Stellar birth rate estimates, Population Synthesis models. Rates quoted below are mean of the distribution.

Need for Long baseline global Network: IndIGO opportunities and benefits

Members: All major GW Detector groups

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..”

•Aside: Invitation to Present on July 10 during GWIC Meeting at Amaldi9 in Cardiff the IndIGO case for GWIC Membership 18

Global Network of GW Observatories improves…

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

GEO: 0.6km

VIRGO: 3km LIGO-LHO: 2km+ 4km LCGT 3 km TAMA/CLIO LIGO-LLO: 4km LIGO-India ?

LIGO-Australia?

LIGO-India: … the opportunity Science Gain from Strategic Geographical Relocation Source localization error

Courtesy: S. Fairhurst

Original Plan 2 +1 LIGO USA+ Virgo LIGO-India plan 1+1 LIGO USA+ Virgo+ LIGO-India LIGO-Aus plan 1+1 LIGO USA+ Virgo+ LIGO-Aus

• • • • • •

Gravitational wave legacy in India

Indian contribution over two decades, to the global effort for detecting GW, internationally recognized on two significant fronts Seminal contributions to source modeling at RRI [Bala Iyer] and to GW data analysis at IUCAA [Sanjeev Dhurandhar] 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 (LSC) for a decade. 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 community strengths

Very good students and post-docs produced who are…

*

Leaders in GW research abroad [Sathyaprakash, Bose, Mohanty] (3) *New faculty at premier institutions in India (6) [Gopakumar, Archana

Pai, Rajesh Nayak, Anand Sengupta, K.G. Arun, Sanjit Mitra, P. Ajith?]

Strong Indian presence in GW Astronomy in the Global detector network where broad international collaboration is the norm  relatively easy to get well trained researchers back

Close interactions with

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

Very supportive International community as reflected in the International Advisory committee of IndIGO –

Chair Abhay Ashtekar

LIGO-Lab participation in IndIGO schools, commitment to training and assisting in high end technology tasks EGO proposal to explore MoU for GW collaboration: Roadmap Meeting on Nov 1-2 ,2011 at IUCAA

• •

High precision Expertise in India

TIFR [C.S. Unnikrishnan] :

– –

High precision experiments and tests of weak forces

Test gravitation using most sensitive torsional balances and optical sensors.

Techniques related to precision laser spectroscopy, electronic locking, stabilization.

– – G.Rajalakshmi (IIA  TIFR, 3m prototype); Suresh Doravari (IIA  LIGO, Caltech expt./AdvLIGO)

IITM [Anil Prabhakar] and IITK [Pradeep Kumar] (EE depts)

– – Photonics, Fiber optics and communications Characterization and testing of optical components and instruments for use in India..

•

RRCAT

– – –

[S.K. Shukla on INDUS, A.S. Raja Rao (exRRCAT)] --UHV

[Sendhil Raja, P.K. Gupta] - Optical system design, laser based instrumentation, optical metrology, Large aperture optics, diffractive optics, micro-optic system design.

[Rijuparna Chakraborty, France

 LIGO/EGO pdf?] Adaptive Optics….

Large experiment expertise in India

• •

RRCAT….

IPR

• [S.B. Bhatt on Aditya and Ajai Kumar] - UHV experience, Lasers…

Support role in large volume UHV system, Control systems etc 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.

• •

Teams at Electronics & Instrumentation Groups at BARC (may be interested in large instrumentation projects in XII plan) Groups at ISRO,…….

Multi-Institutional, Multi-disciplinary Consortium (2009)

Nodal Institutions

1.

2.

3.

4.

5.

6.

7.

8.

CMI, Chennai Delhi University IISER Kolkata IISER Trivandrum IIT Madras (EE) IIT Kanpur (EE) IUCAA, Pune RRCAT, Indore 9.

TIFR, Mumbai 10. IPR, Bhatt

• • •

Others

RRI Jamia Milia Islamia Tezpur Univ

The IndIGO Consortium

IndIGO Council 1.

Bala Iyer 2.

Sanjeev Dhurandhar 3.

4.

C. S. Unnikrishnan Tarun Souradeep ( Chair) (Science) (Experiment) (Spokesperson) RRI, Bangalore IUCAA, Pune TIFR, Mumbai IUCAA, Pune Data Analysis & Theory Instrumentation & Experiment 1.

2.

3.

4.

5.

6.

7.

8.

9.

C. S. Unnikrishnan TIFR, Mumbai

G Rajalakshmi TIFR, Mumbai P.K. Gupta Sendhil Raja S.K. Shukla Raja Rao Anil Prabhakar, Pradeep Kumar, Ajai Kumar RRCAT, Indore RRCAT, Indore RRCAT, Indore ex RRCAT, Consultant EE, IIT M EE, IIT K IPR, Bhatt 10. S.K. Bhatt IPR, Bhatt 11. Ranjan Gupta IUCAA, Pune 12. Bhal Chandra Joshi NCRA, Pune 13. Rijuparna Chakraborty, Cote d’Azur, Grasse 14. Rana Adhikari Caltech, USA 15. Suresh Doravari 16. Biplab Bhawal Caltech, USA (ex LIGO)

1.

2.

3.

4.

5.

6.

7.

8.

9.

Sanjeev Dhurandhar IUCAA Bala Iyer RRI Tarun Souradeep

Anand Sengupta

IUCAA

Delhi University Archana Pai IISER, Thiruvananthapuram Sanjit Mitra JPL , IUCAA K G Arun Rajesh Nayak A. Gopakumar Chennai Math. Inst., Chennai IISER, Kolkata TIFR, Mumbai 10. T R Seshadri 11. Patrick Dasgupta 12. Sanjay Jhingan 13. L. Sriramkumar, 14. Bhim P. Sarma 15. Sanjay Sahay BITS, Goa 16. P Ajith Caltech , USA 17. Sukanta Bose, Wash. U., USA 18. B. S. Sathyaprakash 19. Soumya Mohanty Cardiff University, UK UTB, Brownsville , USA 20. Badri Krishnan Delhi University Delhi University Jamila Milia Islamia, Delhi Phys., IIT M Tezpur Univ . Max Planck AEI, Germany

IndIGO: the goals & roles - I

• •

•

•

Provide a common umbrella to initiate and expand GW related experimental activity and train new technically skilled 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,…

Seek pan-Indian consolidated IndIGO membership in LIGO Scientific Collaboration (LSC) for participation in Advanced LIGO.

Create a Tier-2 data centre in IUCAA for LIGO Scientific Collaboration Deliverables and as a LSC Resource Start collaborative work on joint projects under the IUSSTF Indo-US IUCAA-Caltech joint Centre at IUCAA

IndIGO 3m Prototype Detector

Funded by TIFR Mumbai on campus (2010)PI: C. S.Unnikrishnan (Cost ~ INR 2.5cr) Technology Development and Training Platform

Laser table Vibration isolation schematic Sensing & Control All mirros and beamsplitters are suspended as in the diagram on right 180 cm Power recycling Detector Vacuum tanks F-P cavity 3.2 meters 0.8 m Mirror 60 cm

•

IndIGO: the goals & roles - II

Set up a major experimental initiative in GW astronomy



MOU with ACIGA to collaborate on 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 with offer of LIGO-India and Requirement Document Advanced LIGO hardware for 1 detector to be shipped to India.

Two 4km arm length ultra high vacuum tubes in L configuration India provides suitable site and infrastructure to house the GW observatory, Staffing for installing, commissioning and operation and 10 year Running costs Indian cost ~ Rs 1000Cr



The Science & technology benefit of LIGO-India is transformational

• • •

LIGO-India:

Why is it a good idea?

… for the World

Geographical relocation Strategic for GW astronomy

– – – Increased event rates (x4) by coherent analysis Improved duty cycle Improved Detection confidence – – – Improved Sky Coverage Improved Source Location required for multi-messenger astronomy Improved Determination of the two GW polarizations

Potentially large Indian science user community in the future

– Indian demographics: youth dominated – need challenges – Improved UG education system will produce a larger number of students with aspirations looking for frontline research opportunity at home.

Substantial data analysis trained faculty exists in India and Large Data Analysis Center Facilities are being planned

• • • • •

LIGO-India:

Why is it a good idea?

……..

for India

Jump start direct participation in GW Observations & Astronomy Provides an exciting challenge at the International forefront of experimental science. Can tap and siphon back the extremely good UG students trained in India. (a cause for `brain drain’). – – 1 st yr summer intern 2010  MIT for PhD Indian experimental scientist  Postdoc at LIGO training for Adv. LIGO subsystem; Another Postdoc under consideration in LIGO & EGO

Experimental expertise related to GW observatories will thrive and attain high levels due to LIGO-India.

Challenging endeavour involving unforgiving technology mandates symbiotic interplay of Engineering and Science disciplines.. Revival of Advanced Instrumentation Inclusive cooperation between Basic science research Institutes, High Technology DAE Labs, ISRO,..Educational IISER’s and Universities for highly visible frontier research

Science Payoffs

• SKA : Pulsars timing and GW background, GW from Pulsars ,… • Testing Einstein’s GR in strong and time-varying fields • • • • • • • – Testing Black Hole phenomena X-ray satellite (AstroSat) : Spacetime near Black Holes, NS, …. – GRB triggers from GW – –

Neutron star coalescence events

Thirty Meter Telescope: Resolving multiple AGNs, optical follow-up, … Understanding most energetic cosmic events ..

Supernovae, Gamma-ray bursts, LMXB’s, Magnetars

LSST: Astro-transients with GW triggers, Cosmic distribution of dark

New cosmology..SMBHB’s as standard sirens..

–

EOS of Dark Energy Phase transition related to fundamental unification of forces

–

Multi-messenger astronomy

–

The Unexpected !

Summary

(Part 1)

• • LIGO-India will raise public 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. Einstein@home; Black Hole Hunter…

Opportune to a launch a promising field (GW astronomy) with high end technological spinoffs, well before it has obviously blossomed. Once in a generation unique

opportunity to host in India a sophisticated International Experiment straining to hear the feeble notes of Einstein’s GW Symphony playing in the universe and deciphering the dark secrets that light or EMW can never reveal.. A GREAT opportunity but a very sharp deadline of 31 Mar 2012. LIGO-Lab needs to seek NSF nod latest by Dec 2011

–

We must be ready with credible plan proposal from India by Nov 2011

End of Part I

Thank you !!!

Over to Tarun …

IndIGO Advisory Structure

Committees: 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) 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 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)]

LIGO-India: … the opportunity Strategic Geographical relocation: science gain Polarization info Homogeneity of Sky coverage

Courtesy: S.Kilmenko & G. Vedovato

LIGO-India: … the opportunity Strategic Geographical relocation: science gain Sky coverage : Synthesized Network beam (antenna power)

Courtesy: B. Schutz

LIGO-India: … the opportunity Strategic Geographical relocation: science gain Sky coverage: ‘reach’ /sensitivity in different directions

Courtesy: B. Schutz

Strategic Geographical relocation: science gain Network HHLV HILV AHLV Mean horizon distance Detection Volume Volume Filling factor Triple Detection Rate(80%) Triple Detection Rate(95%) Sky Coverage: 81% Directional Precision

1.74

8.98

41.00% 4.86

7.81

47.30% 0.66

1.57

8.77

54.00% 5.95

8.13

79.00% 2.02

1.69

8.93

44.00% 6.06

8.28

53.50% 3.01

Using GWs to Learn about the Source: an Example Over two decades, RRI involved in computation of inspiral waveforms for compact binaries & their implications and IUCAA in its Data Analysis Aspects.

Can determine

• • •

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

Gravitational wave Astronomy :

vit

GWIC Roadmap Document

Unique 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.

Largest Ultra-high vacuum system 10^-9 torr (1picomHg) in the region.

Such a UHV system will provide industry a challenge and experience.

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

Gravitational wave Astronomy :

vit

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

GWIC Roadmap Document

23 July 2011 Dear Bala: I am writing to invite you to attend the next meeting of the Gravitational Wave International Committee (GWIC) to present the GWIC membership 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 membership ……

Invitation to Present IndIGO case for GWIC Membership on July 10 at GWIC meeting at Cardiff

Space Time as a fabric

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

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

B

Path A Path B

A Difference in distance of Path A & B



Interference of laser light at the detector (Photodiode)

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 relativity.

Initial LIGO Sensitivity Goal

•

Strain sensitivity <3x10

-23 1/Hz 1/2

at 200 Hz

 Sensor Noise » Photon Shot Noise » Residual Gas  Displacement Noise » Seismic motion » Thermal Noise » Radiation Pressure 52

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



(Hannover group, Germany) 180 W >> 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

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 any Detector

•

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

GW



Astronomy

link

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 events Bursts (SN, GRB), mergers, accretion, stellar cannibalism ,… • Extremely Weak interaction, hence, has been difficult to detect directly But also implies GW carry unscreened & uncontaminated signals

Scientific Payoffs

Advanced 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

Principle behind Detection of GW

Dear Prof. Kasturirangan,

LIGO-India from LIGO

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 Consortium, for a Joint Partnership venture to set up an Advanced gravitational wave detector at a suitable Indian site. In what follows this project is referred to as LIGO-India. The key idea 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 US Advanced LIGO observatories.

LIGO-India could be operational early in the lifetime of the advanced versions of gravitational wave observatories 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 of this new window on the universe. The present proposal promises to achieve this at a fraction of 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.

Binary Pulsars..NS-NS Binary

Pulsar companion

High quality observational data that GW exist….

• • • •

Indian Gravitational wave strengths

Very good students and post-docs produced from this.

* Leaders in GW research abroad [Sathyaprakash, Bose, Mohanty] (3) * *New faculty 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 characterization 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 presence in GW Astronomy with Global detector network  broad international collaboration is the norm  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 International community reflected in International Advisory committee of IndIGO – Chair Abhay Ashtekar EGO-IndIGO meeting on Nov 1-2 ,2011 at IUCAA to explore collaboration

LIGO-India:

Why is it a good idea?

……..

for India

• • • experimental science. Can tap and siphon back the extremely good UG students trained in India.

drain’).

(a cause for `brain

– 1 • • st yr summer intern 2010 

X-ray satellite (AstroSat) :

subsystem MIT for PhD  Postdoc at LIGO training for Adv. LIGO Spacetime near Black Holes, NS, ….

Gamma ray observatory:

GRB triggers from GW

Indian experimental expertise related to GW observatories will

thrive and attain high levels due to

• •

INO:

cross correlate neutrino signals from SN event

LSST: A

.

Symbiotic interplay of Engineering and Science disciplines for a challenging endeavour involving • unforgiving technology

Jump start direct participation in GW Observations & Astronomy

LIGO-India:

Why is it a good idea?

……..

for India

• • • • Provides an exciting challenge at an International forefront of experimental science. Can tap and siphon back the extremely good UG students trained in India.

(a cause for `brain drain’).

– 1 st 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

.

Symbiotic interplay of Engineering and Science disciplines for a challenging endeavour involving unforgiving technology

Jump start direct participation in GW Observations & Astronomy

Indirect evidence for Gravitational waves

Binary pulsar systems emit gravitational waves

•

leads to loss of orbital energy

• •

period speeds up 14 sec from 1975-94

•

High quality Pulsar Timing Data..

measured to ~50 msec accuracy deviation grows quadratically with time

Pulsar companion

Hulse and Taylor Results for

PSR1913+16

Oscillatory Tidal Effect of GW on a ring of test masses If Interferometer mirrors are the test masses

•Path difference due to tidal distortion  phase difference •

The effects of gravitational waves appear as a fluctuation in the phase differences between two orthogonal light paths of an interferometer.

Equal arms: Dark fringe Unequal arm: Signal in PD

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. Will 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. Increase international collaborations in Indian research & Potential for Indian Science Leadership in the Asia-Pacific region.

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