Gravitational Physics

Gravitational Physics

the dynamics of spacetime

FOM, April 7, 2009 - jo@nikhef.nl

 Motivation

 Aim and focus

 Composition of consortium

 Requested positions versus aim

 Coherence and added value

Outline

Einstein gravity :

Gravity as a geometry

Space and time are physical objects

8

G _   T _

 Gravitation

–

Least understood interaction

–

Large world-wide intellectual activity

– Theoretical: ART + QM, Cosmology

– Experimental: Interferometers on Earth and in space

 Gravitational waves

–

Dynamical part of gravitation, all space is filled

–

Very large energy, almost no interaction

–

Ideal information carrier, almost no scattering or attenuation

–

The entire universe has been transparent for GWs, all the way back to the Big Bang

Motivation

Aim and focus

 Scientific promise

–

Direct discovery of gravitational waves

–

Signals from the early Universe

–

Towards gravitational wave observatories

 Bundle existing strengths

–

(astro)particle physics: experiment and theory

–

Astrophysics, astronomy and cosmology

 Multi-disciplinary physics program

To achieve deep understanding of gravitation and spacetime

Focus on 3 activities

R.A. Hulse and J.H. Taylor Jr (1993)

The horizon (best orientation) for a binary system of two 10 solar mass black holes is 63 Mpc

Compare to square root of Planck time: t

 l

c   G

/ c

 5  10

Hz

For capability to study details at Planck scale h  t

 2 . 3  10

Hz

Interferometers – sensitivity

6

100 million light years

Enhanced LIGO

~2009

Advanced LIGO ~2014

LIGO today

Credit: R.Powell, B.Berger

 Nikhef contributions to Virgo+ :

–

Automatic Alignment electronics

–

Thermal compensation simulations

–

Input Mode Cleaner optics

1 e v/w ee k – 1 ev /da y e xp ec ted

Activity 1 - towards discovery

 Probable sources

–

Binary neutron star coalescence

–

Binary black holes mergers, supernovae, pulsars

 Horizon (Virgo+)

–

BNS: 150 Mpc (optimal orientation)

–

BBH: 750 Mpc (optimal orientation)

 BNS Rates: (most likely and 95% interval)

–

Initial Virgo (30Mpc) 1/100yr (1/500 - 1/25 yr)

–

Enhanced LIGO (60Mpc) 1/10yr (1/50 - 1/2.5yr)

–

2009: Virgo+ limit (150Mpc) 1.2/yr (1/4 - 5/yr)

–

2014: Advanced detectors (350Mpc) 40/yr (8 - 160/yr)

Kalogera et al; astro-ph/0312101; Model 6

 BBH and other sources rates are more difficult to predict

Astronomy: we know GW

sources exist!

Activity 1 - direct discovery of GW

Design Study Proposal approved by EU within FP7 Large part of the European GW community involved

EGO, INFN, MPI, CNRS, NIKHEF, Univ. Birmingham, Cardiff, Glasgow

Recommended in Aspera / Appec roadmap

–

3 spacecraft in Earth-trailing solar orbit separated by 5 x10

km.

–

Measure changes in distance between fiducial masses in each spacecraft

–

Partnership between NASA and ESA

–

Launch date ~2018+

GW roadmap: Golden Age of Gravitational Physics

Activity 2 - GW antenna in space - LISA

Rotating Neutron Stars

Difference of 10

in wavelength:

Like difference between X-rays and IR!

VIRGO LIGO LISA

LISA will see all the compact white-dwarf and neutron-star binaries in the Galaxy (Schutz)

Complementarities of GW detectors

Is Einstein’s theory still right in these conditions of

extreme gravity? Or is new physics awaiting us?

Chandra - Each point of x-ray light is a Black Hole !

What happens at the edge of a Black Hole?

Science goals

Dark energy and matter interact through gravity

We do not know what 95% of the universe is made of!

What is the mysterious Dark Energy pulling the Universe apart?

Science goals

Gravitational Waves Can Escape from Earliest Moments of the Big Bang

Inflation

(Big Bang plus 10^-34 Seconds)

Big Bang plus 380,000 Years

gravitational waves

Big Bang plus 14 Billion Years

light

Now

What powered the Big Bang?

Science goals

 Theoretical (astro)particle physics community

–

GW, inflation, string theory, cosmic defects

–

Jan Willem van Holten et al. (Nikhef, Leiden)



Provide templates, spectra, etc.

–

Participate in Virgo – LIGO analysis

Activity 2: Signals from inflation and phase transitions

G. Koekoek

 SRON

–

LISA Pathfinder

 Theoretical (astro)particle physics community

–

GW, inflation, string theory, cosmic defects

 Westerbork

–

EPTA

 NOVA

–

Leiden Univ.: PTA (Levin)

–

UvA: GW emission NS (Watts)

 ESA – Noordwijk

–

LISA coordination (Jennrich)

 Leiden Univ.

–

MiniGrail (Frossati)

 Nikhef

–

Strategic plan, Review 2007

GW in the Netherlands

 Periodic sources analysis – GRID

– VU – Nikhef – RU

 Coalescing binaries – BNS, BBH

– Nikhef – VU – RU

 Advanced Virgo upgrade

– Nikhef – VU

 Early Universe – theory and analysis

– Nikhef - VU

 Source populations ET and LISA

– RU – Nikhef – VU

All members bring in relevant experience

Consortium

Discovery

ET, LISA Early Universe

H.J. Bulten Analysis, LISA T. Ketel Optics J. van den Brand Coordinator D. Rabeling (postdoc) Discovery, ET G. Koekoek (PhD) Theory

T. Bauer Optics H. van der Graaf Suspension J.W. van Holten Theory New staff member Analysis M. Beker (PhD) ET S. van der putten (PhD) Analysis

J. Kuipers Sources G. Nelemans LISA

LISA



Periodic sources analysis – GRID

– H.J. Bulten (VU), S. van der Putten (PhD)



Coalescing binaries – BNS, BBH

– JvdB, Nikhef staff, pd1 (3 yr), PhD1, PhD2



Advanced Virgo upgrade

– T. Bauer (Nikhef), T. Ketel (VU), JvdB, M. Beker (PhD), all PhD and pd



Early Universe – theory and analysis

– J.W. van Holten (Nikhef), M. Postma (Nikhef), G. Koekoek (PhD), PhD3, pd1 (3 yr)



Source populations ET and LISA

– J. Kuipers (RU), G. Nelemans (RU), D. Rabeling (VU), pd2 (5 yr), PhD4



Multi-messenger analysis (Lofar, optical, UC binaries)

– G. Nelemans (RU), H.J. Bulten, PhD5



Running budget

– Annual contribution to Virgo



Investment budget: 500 k€ (Nikhef NWO MG 1.5 M

)

– Advanced Virgo: Cryo links, seismic isolation, optical systems

6 year program

6 PhDs, 2 postdocs

Requested resources – projects

 Ambitious program

–

Combines resources from universities and research institute

 Strong position at international forefront

–

Program provides focus, collaboration and coherence

–

Timing: Advanced Virgo and LIGO decided now

 Attractive context for advanced research

–

Excellent environment for postdocs, students, guests

–

High quality training

 Broadening of scientific experience

–

Experimental physics, analysis, GRID computing, astronomy, astrophysics, cosmology, theory

 Organize national GW community

–

Annual Dutch GW meeting through Nikhef

 Links to other programs

–

Multi-messenger astroparticle physics (with KM3Net)

Added value of FOM program

Backup slides

LISA

Theoretical Astroparticle physics

LISA

 LIGO

 The largest single enterprise undertaken by NSF.

 Total capital investment about $ 300 million.

 Exploitatie about M$ 30/jaar.

 Enhanced LIGO (2008) is approved, financed and installed.

 Advanced LIGO (2012) is approved, financed (for M$ 210).

 LIGO Science Collaboration (LSC) consists of >600 physicists and astronomers; > 45 institutes.

 Quality of participants is excellent (MIT, Caltech, Stanford, etc.).

 Three interferometers (ITF): 2 with 4 km arms, 1 with 2 km arms.

 All ITFs achieved design sensitivity.

 Virgo

 Investment about MEuro 100 by France and Italy.

 Exploitation about MEuro 10/yr

 Virgo+ (2008) is approved and financed.

 Advanced Virgo (2012) approval in 2009.

 1 ITF with 3 km arms.

 ITF sensitivity at design value for f > 700 Hz.

 LISA

 Lisa Pathfinder cost about MEuro 240.

 Lancering is scheduled for 2010.

 LISA 3 satellites costs about Euro 1.5 miljard.

 Highest scientific priority of the 11 Beyond Einstein missions.

 Decadel review ongoing in USA.

GW fact sheet

 Einstein Telescope

 CDS approved in FP7 for 3M€

 Highest scientific priority of 51 proposals

 JvdB leads WG1 on site selection

 Appears on ASPERA roadmap as 1 of Magnificent Seven

 GW physics

 APS Topical group (>1000 members)

 Future APS division?

 NL part of EGO consortium?

NRC

De Volkskrant

Technisch weekblad Kijk

Intermediair

Teleac Radio5

Civiele Techniek

Outreach – 2008

GW Program Management

 Management Structure

–

Clear structure established to realize Mass and Focus

–

Initial MT composition: GN, JWvH and JvdB (chair)

 MT tasks

–

Monitor progress in various scientific activities

–

Allocation of resources (re-discuss annually)

–

Provide steering

–

New scientific developments

–

Note: 1 PhD not allocated

–

Monitor finances

–

Outreach

 Work towards a national GW community

–

Nikhef has a role here (annual and quarterly meetings)

 Links to other programs

–

Multi-messenger astroparticle physics (e.g. with KM3Net)