LIGO-India Detecting Einstein’s Elusive Waves Opening a New Window to the Universe

1. LIGO-IndiaDetecting Einstein’s Elusive WavesOpening a New Window to the Universe IndIGO Consortium (Indian Initiative in Gravitational-wave Observations) An Indo-US joint mega-project concept proposal Version: BRI Jun 10, 2011 www.gw-indigo.org

2. Space Time as a fabric In 1916, Albert Einstein published his famous Theory of General Relativity, the theory of gravitation. 4-dimensional space-time (the normal three dimensions of space, plus a fourth dimension of time). His theory describes how space-time is affected by mass and also how mass affects spacetime. Matter tells spacetime how to curve, and spacetime tells matter how to move.

3. Space Time as a fabric

4. Einstein’s General theory of relativity • is the most • beautiful & successful • theory of modern physics. • It has matched all tests of Gravitation remarkably well.

5. What happens when matter is in motion?

6. Einstein’s theory predicts Matter in motion fluctuation in the curvature of space-time which propogates as a wave Space-time ripples or gravitational waves

7. Binary Neutron stars Pulsar companion

8. GW from Binary Neutron stars

9. Indirect evidence for Gravity waves Won the Nobel prize in 1993 !!! Binary pulsar emits gravitational waves leads to loss of orbital energy period speeds up 14 sec from 1975-94 measured to ~50 msec accuracy deviation grows quadratically with time Hulse and Taylor Results for PSR1913+16

10. Effect of GW on test masses

11. Effect of GW on a ring of test masses Interferometer mirrors as test masses

12. Path A Path B Detecting GW with Laser Interferometer B A Difference in distance of Path A & B Interference of laser light at the detector (Photodiode)

13. Path difference  phase difference Equal arms: Dark fringe The effects of gravitational waves appear as a fluctuation in the phase differences between two orthogonal light paths of an interferometer. Unequal arm: Signal in PD

14. Challenge of Direct Detection Gravitational waves are very weak! Gravitational wave is measured in terms of strain,h (change in length/original length) Expected amplitude of GW signals Measure changes of one part in thousand-billion-billion!

15. GEO: 0.6km VIRGO: 3km LIGO-LHO: 2km, 4km TAMA: 0.3km LIGO-LLO: 4km LIGO-Australia? GW Astronomy with Intl. Network of GW Observatories 1. Detection confidence 2. Duty cycle 3. Source direction 4. Polarization info. LCGT?? LIGO-India ?

16. A Century of Waiting • Almost 100 years since GW were theoretically predicted By Albert Einstein but still no direct experimental confirmation a la Hertz • Reason is connected to two fundamental differences between EM and • Gravitation: • - The weakness of the gravitational interaction relative to EM (10􀀀39) • -The spin two nature of gravitation compared to the spin one nature • of EM that forbids dipole radiation in GR. • Implies low efficiency for conversion of mechanical energy to gravitational radiation. And feeble effects of GW on any potential detector. • A GW Hertz experiment is ruled out and it is only signals produced by astrophysical systems where there are potentially huge masses accelerating very strongly that are likely sources.

17. Gravitational Waves Exist! High quality data which is proof that GW exist. In 1974 Hulse and Taylor, discovered the Binary Pulsar 1913+16. The system has now been monitored for 30 years. Orbital period slowly decreasing at just the rate predicted by GR for emission of GW!!! Hulse and Taylor received Nobel Prize for this (1993). ADD FIGURES

18. Laser Interferometric Gravitational Wave Detectors? • Binary Pulsars establish Reality of Grav Radn. Validity of GR in Strong Fields. Excellent Evidence but Evidence is Indirect • Can detectors be built to attempt a Direct detection of these GW?? • GW are transverse and tidally distort a system in directions • perpendicular to propagation direction. • Effect measured by the Dimensionless strain h = 2( Delta L)/ L, it produces • For a typical NS binary in Virgo cluster (18 Mpc; 5.6 x 10^20 km) • h = 4G/ c^4 Knonsph/D ~ (2 GM/ Rc^2) (GM/Dc^2) ~ 1.5 x 10^-21 • The miniscule strain and associated tiny displacement must be • measured to detect the GW. • Weber's Bar detectors (Narrow band); • Today's Laser Interferometric Detectors ( Broad Band) • As a GW passes, the arm lengths of km scale ITF change (10^-18m) • tidally causing the interference pattern to change at the photodiode • Direct detection of GW - • First mandate of Laser Interferometric GW detectors • Promised and Real Excitement - New Observational Window and • Tool for Astrophysics; Experimental Probe for Basic Physics

19. Change in Length manifests as Change in Transmitted Light GW detection is about seeing the biggest things that ever happen by measuring the smallest changes that have ever been measured - Harry Collins.

21. LIGO and Virgo TODAY Field reached a Milestone with decades-old plans to build and operate large interferometric GW detectors now realized at several locations worldwide Unprecedented sensitivity allows one to place Upper Limits on GW from a variety of Ap sources. Improve on Spindown of Crab, Vela pulsars, Big Bang nucleosynthesis bound on Stochastic GW..

22. Expected Annual Coalescence Rates In a 95% condence 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.

23. Laser Interferometer GW Observatory 40 kg Fused silica mirrors (USA) Seismic isolation Stacks (GEO, UK) Optics & controls (USA) 4 km: 1.2m diameter high vaccum tubes India Fig from LIGO-AUS report? 180 W (Germany)

24. Schematic Optical Design of Advanced LIGO detectors

25. Era of Advanced LIGO detectors: 2015 If retained get better res picture

26. Gravitational wave Astronomy : • Synergy with other major Astronomy projects: • SKA: Radio : Pulsars timing, • X-ray satellite (AstroSAT) • Gamma ray observatory • Thirty meter telescope: gamma ray follow-up,… Courtesy: B. Schutz, GWIC Roadmap Document 2010

27. INDIGO:the goals • Major experimental science science initiative in GW astronomy • 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 armlength high vacuum tubes in L config. • Indian cost ~Rs 1000Cr • Earlier plan: Partnership 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. • Consolidated IndIGO membership of LIGO Scientific Collaboration + propose creating a Tier-2 data centre for LSC in IUCAA + IUSSTF IndoUS joint Centre at IUCAA with Caltech (funded) • 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 | High Vaccum & controls at RRCAT, IPR, BARC, ISRO, …. • UG summer internship at Natn. & Intl GW labs & observatories. • PostgradIndIGO schools, specialized courses,…

28. Multi-Institutional, Multi-disciplinary Consortium • CMI, Chennai • Delhi University • IISER Kolkata • IISER Trivandrum • IIT Madras • IIT Kanpur • IUCAA • RRCAT • TIFR • RRI • IPR, Bhatt • JamiaMiliaIslamia • TezpurUniv

29. The IndIGO Consortium IndIGO Council Bala Iyer ( Chair) RRI, Bangalore Sanjeev Dhurandhar (Science) IUCAA, Pune C. S. Unnikrishnan (Experiment) TIFR, Mumbai Tarun Souradeep (Spokesperson) IUCAA, Pune Data Analysis & Theory Sanjeev Dhurandhar IUCAA Bala Iyer RRI Tarun Souradeep IUCAA Anand Sengupta Delhi University Archana Pai IISER, Thiruvananthapuram Sanjit Mitra JPL , IUCAA K G Arun Chennai Math. Inst., Chennai Rajesh Nayak IISER, Kolkata A. Gopakumar TIFR, Mumbai T R Seshadri Delhi University Patrick Dasgupta Delhi University Sanjay Jhingan Jamila Milia Islamia, Delhi L. Sriramkumar, Phys., IIT M Bhim P. Sarma Tezpur Univ . P Ajith Caltech , USA Sukanta Bose, Wash. U., USA B. S. Sathyaprakash Cardiff University, UK Soumya Mohanty UTB, Brownsville , USA Badri Krishnan Max Planck AEI, Germany Instrumentation & Experiment C. S. Unnikrishnan TIFR, Mumbai G Rajalakshmi TIFR, Mumbai P.K. Gupta RRCAT, Indore Sendhil Raja RRCAT, Indore S.K. Shukla RRCAT, Indore Raja Rao ex RRCAT, Consultant Anil Prabhakar, EE, IIT M Pradeep Kumar, EE, IIT K Ajai Kumar IPR, Bhatt S.K. Bhatt IPR, Bhatt Ranjan Gupta IUCAA, Pune Rijuparna Chakraborty, Cote d’Azur, Grasse Rana Adhikari Caltech, USA Suresh Doravari Caltech, USA Biplab Bhawal (ex LIGO)

30. IndIGO Advisory Structure 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 (AIGO, 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 (AIGO, 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) 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) INSERT BOX

31. LIGO-India:Why is it a good idea?for India • Has 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!) • AIGO/LIGO/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. • For once, may be 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 International Experiment here.

32. LIGO-India:Why is it a good idea?… for the World • Strategic geographical relocation for GW astronomy • sky coverage gain • distance: • duty cycle: • 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.

33. GWIC: Gravitational Wave International Committee Courtesy: B. Schutz: GWIC Roadmap Document

34. Indo-Aus.Meeting, Delhi, Feb 2011

35. 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……

36. LIGO-India: the concept … • LIGO Lab approached with concept proposal for joint mega-project --- strategic geographical relocation of • Advanced LIGO interferometer detector funded and ready to be shipped by US • Indian contribution in infrastructure : • site • vacuum system • Related Controls • Data centre • trained manpower for installation, commissioning and running for 10 years

37. The Science payoffs • New Physics, New Astronomy, New Astrophysics, New Cosmology.. • A New Window ushers a new era of exploration.. • Testing Einstein's GR.. • Black hole phenomena.. • Understanding nuclear matter by neutron star EOS • Neutron star coalescence events • Listening to most energetic events in the universe. • Supernovae, Gamma ray bursts, Magnetars • New Cosmology: Standard Sirens..Determine EOS of Dark energy • Multi-messenger Astronomy • The Unexpected!!

38. The 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. • Ultrahigh reflective coatings.. • Vibration isolation and suspension..Applications for mineral • prospecting • Sqeezing and QM limits • Ultra high vacuum system 10^-9 torr.. • Largest in this region • Computation Challenges f

42. LIGO-India: … the Opportunity • Part of a fundamental scientific discovery : direct detection of gravitational radiation • Part of “historic” launch of a new window of Astronomy • LIGO-India: Southernmost, hence, Unique role in the Intl. GW observatory network. • Full detector at about half the cost is the naïve calculation. • Adv. LIGO detector system is worth 15 years of challenging R &D – price tag? • Indian Labs & Industry

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

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

45. LIGO-India: … the opportunity Strategic Geographical relocation Source localization error 5-15 degrees to ~degree !!! Ellipses version as in LIGO-Aus proposal ?

46. LIGO-India: … the opportunity Strategic Geographical relocation Polarization info Sky coverage ?