Discussion of GWIC 3G Report: acceptance and follow-up actions Sheila Rowan GWIC Chair Dawn V Cascina, 26 - 27th May 2019

Charge, progress and draft recommendations of the draft 3G study Next steps.

Science case Charge: Commission a study of ground-based gravitational wave science from the global scientific community, investigating potential science vs architecture vs. network configuration vs. cost trade-offs, recognizing and taking into account existing studies for 3G projects (such as ET) as well as science overlap with the larger gravitational-wave spectrum Progress: Draft report leaves no doubt that there is a wealth of science to be delivered by detectors ~X10 more sensitive than the current ‘Advanced’ instruments Outcomes: Clear advantage with 3 x 3G detectors Global network delivers the optimum science

R&D Charge: Develop and facilitate coordination mechanisms among the current and future planned and anticipated ground-based GW projects, including identification of common technologies and R&D activities as well as comparison of the specific technical approaches to 3G detectors. Possible support for coordination of 2G observing and 3G construction schedules. Progress: Substantial evaluation of current status of technology and R&D and identification of specific areas of common global interest Recommendations: R1 An international 3G R&D coordination committee should be formed, with broad and inclusive membership representing GW groups across the world. A series of workshops on enabling technologies should be held in order to stimulate exchange of ideas and allowing (if deemed useful) for coordination of the person-power intensive experimental activities. Each of the major R&D tasks should generate a list of goals with quantitative metrics, timelines and required resources. Activities requiring global collaboration and coordination should be laid down and pathways identified.

R&D Recommendations: R2: International consortia should be formed to work on key issues with industry partners, establish a governance and organisational structure with teeth (i.e. controls purse strings) and seek funding through joint proposals submitted across funding agencies. R3: National funding agencies should increase funding (staff and instrumentation) to enable the required long-term research programmes at relevant laboratories and prototype interferometers. R4: Existing GW collaborations should integrate 3G R&D tasks and corresponding deliverables into their programs in order to ensure sufficient support for the long-term future of the field. In particular, over the next 5 years, mature 2G enabling technologies (e.g. 1064 nm laser, fused silica optics, coatings) should be demonstrated to be up-scaled and ready for application in 3G facilities.

Networking Charge: organize and facilitate links between planned global 3G projects and other relevant scientific communities, including organizing: town hall meetings to survey the community dedicated sessions in scientific conferences dedicated to GW physics and astronomy focused topical workshops within the relevant communities Progress: Regular activity in the above areas – reaching out to the astronomy, particle astrophysics and particle physics communities Co-ordinated submissions from or endorsed by GWIC to roadmapping and planning exercises over the last few years.

Agency Interfacing and Advocacy Charge: identify and establish a communication channel with funding agencies who currently or may in the future support ground-based GW detectors; communicate as needed to those agencies officially through GWIC on the scientific needs, desires, and constraints from the communities and 3G projects (collected via 1) – 3) above) structured in a coherent framework; serve as an advocacy group for the communities and 3G projects with the funding agencies. Progress (as an action based charge there is no written report - examples include): Formation of the Gravitational Wave Agencies Correspondents group Multiple presentations by GWIC to GWAC (2016, onwards) Joint meetings with GWAC and APPEC representatives at DAWN IV, V Presentation at APPEC General Assembly, Barcelona (Dec 2017) Upcoming invitation to GWIC to present to the ‘Group of Senior Officials’ meeting, (3rd June, Roscoff) Recommendations: This need continues to exists with GWIC currently still well placed to facilitate communication Future role tbd in the context of governance recommendations

Governance Evaluation Charge: By applying knowledge of the diverse structures of the global GW community, propose a sustainable governance model for the management of detector construction and joint working, to support planning of 3rd generation observatories. Progress: draft report delivered. Three example options for international governance models. Recommendations: Experience suggests arriving at a global governance model is an evolution process, emerging from sustained collaboration between project leaders and funding agencies. Phased approach proposed to walk down that path starting now.

Next steps on the report We are here May 26 - present major conclusions (in draft form) at the Dawn V workshop in Cascina for community discussion, feedback End of May - send out reports to a broad list of reviewers for feedback by June 30.  Also circulate broadly to relevant communities (LSC, Virgo, KAGRA, LISA, ..) for input/comment/feedback July 7 - present a mature draft of the report to GWIC, present at Amaldi August 30 - deliver final version of the report (Caveat: the GWIC 3G Committee may revise these dates.) Aim to reach a consensus on the contents of the report - tune and make complete.

Next steps on future planning – topics for discussion A common key recommendation is around a proposal for the continuation/change/end of the GWIC 3G committee Addressed to the field: Form an international (non-legal) umbrella organization Charge people to write the charter R&D as one first focus of this group    Advocacy: dedicated effort: team whose #1 priority is 3G - advocating, planning, seeking funding, standing up R&D programs, and coordinating across the globe ? in the early phase, before a common management/governance structure is still missing, should we include in the management team of each project a delegate of the other project(s)?

Next steps on future planning – topics for discussion Addressed to the Agencies Apportion resource/develop joint tools, and for funding R&D at an international or even global level Work with the community on advancing common governance structures Seek to lay placeholders within the available infrastructural resource models for relevant scale of future GW observatories