The Quest for Gravitational Waves: a global strategy Eugenio Coccia U. of Rome “Tor Vergata” INFN Gran Sasso Science Institute Past Chair Gravitational Wave International Committee

https://gwic.ligo.org/ GWIC is now an IUPAP Working group (WG11) Sheila Rowan (Glasgow) is the new Chair since August 2015

2030? From LISA to eLISA eLISA Savings mainly in weight, launch cost. Two active arms, not three; Smaller arms (1Gm, not 5Gm); Re-use LISA Pathfinder hardware; 2030?

THE GWIC GLOBAL PLAN Advanced Detectors (LIGO, VIRGO) will initiate gravitational wave astronomy through the detection of the most luminous sources - compact binary mergers. Third Generation Detectors (ET and others) will expand detection horizons and provide new tools for extending knowledge of fundamental physics, cosmology and relativistic astrophysics. Observation of low frequency gravitational wave with eLISA will probe the role of super-massive black holes in galaxy formation and evolution

for the operation of the LIGO-Virgo network over the next decade Plausible scenario for the operation of the LIGO-Virgo network over the next decade

Localization expected for a BNS system 2016/17 2017/18 80 Mpc 2019+ 2022+ 160 Mpc Localization expected for a BNS system The ellipses show 90% confidence localization areas, and the red crosses show regions of the sky where the signal would not be condently detected.

8 Recommendations to GWIC to guide the development of the field 8.5 Toward a third-generation global network “Background— The scientific focus of a third-generation global network will be gravitational wave astronomy and astrophysics as well as cutting edge aspects of basic physics. Third-generation underground facilities are aimed at having excellent sensitivity from ~1 Hz to ~104 Hz. As such, they will greatly expand the new frontier of gravitational wave astronomy and astrophysics. In Europe, a three year-long design study for a third-generation gravitational wave facility, the Einstein Telescope (ET), has recently begun with funding from the European Union.

The Einstein GW Telescope The ET project aims to the realization of a 3rd generation GW observatory The conceptual design phase has been performed in the 2008-2011 years, thanks to the support (3M€) of the European Commission under the FP7-design studies framework The design document has been delivered in July 2011 ~400 pages describing the main characteristics of the observatory http://www.et-gw.eu/etdsdocument ET-Flagship

ET International collaboration Participant Country EGO Italy France INFN MPG Germany CNRS University of Birmingham UK University of Glasgow Nikhef NL Cardiff University The initial seed of the ET collaboration was (2008) composed by the scientists of the 8 proposing institutes ET-Flagship

ET International collaboration Now the ET science team includes more than 220 physicists ET Author list: ET-Flagship

Beyond Advanced Detectors Let suppose to gain a factor 10 wrt the Advanced detectors: What could we do? Astrophysics: Measure in great detail the physical parameters of the stellar bodies composing the binary systems NS-NS, NS-BH, BH-BH Constrain the Equation of State of NS through the measurement of the merging phase of BNS of the NS stellar modes of the gravitational continuous wave emitted by a pulsar NS Contribute to solve the GRB enigma Relativity Compare the numerical relativity model describing the coalescence of intermediate mass black holes Test General Relativity against other gravitation theories Cosmology Measure few cosmological parameters using the GW signal from BNS emitting also an e.m. signal (like GRB) Probe the first instant of the universe and its evolution through the measurement of the GW stochastic background Astro-particle: Contribute to the measure the neutrino mass Constrain the graviton mass measurement ET-Flagship