The identification of site candidates will be another focus in this phase.
Impact assessments and acquisition feasibility will be pursued. Civil
engineering will investigate the Newtonian noise and site preparation plans
both generically and for target sites. Parametric estimates of the cost will
be developed with substantial engineering backup.

Inextricably linked with the site search for CE is the need to build
relationships with the Indigenous Peoples to whom the land belongs. These
relationships will inform the CE team’s approach to identifying suitable
sites, and how one could proceed with integrating CE into the land in a way
which is not just compatible with the terrain and culture but forms a
partnership that is productive and positive for all the parties involved.
Effort will be made to avoid barriers – physical, organizational, or
philosophical – between CE and the environment.

The vacuum system for CE is the largest cost element and also one that impacts
the implementation approach. Prototype tests and modeling will be undertaken,
and again parametric cost estimates developed.

The initial detector designs will be refined. Insights from the continued work
with the current detectors will be incorporated, and where feasible
implementation of Cosmic Explorer designs will be integrated into LIGO for
testing. The flowdown of observational science goals will influence the
priorities in the design. Seismic isolation and thermal noise considerations
will drive the isolation and suspension systems. Mirror coatings are likely to
drive R&D, with crystalline coatings one path to explore. Interferometer
layout and control will be detailed.

###### Preliminary Design Phase

The Preliminary Design will iterate on the Conceptual Design phase products.
The site selection, anticipated to be an NSF activity, will be supported by
the CE team; Indigenous Peoples will continue to play a key role. The design
options for the detector, vacuum system, and civil construction will be down-
selected to the optimal subset. A bottom-up cost estimate will be made, risks
assessed, and a detailed Project Execution Plan (PEP) developed.

A transition to the target Project management organization will be completed
during this phase.

###### Final Design Phase

The relationships of the now-firm Cosmic Explorer Observatory management with
the scientific community will be established, and plans crafted to create a
sustainable and diverse team and community. The CE presence at the sites will
grow as the team is integrated into the local communities, and the local
communities engaged in the CE Project. The PEP will be finalized. Vendors for
the key items will be identified and the logistics of the construction process
determined.

At the close of this process, the Project should be well underway and the
installation, commissioning, and operations activities will become the new
focus.

###  5.6 Round Table on Data Access Models

Duncan Brown (chair), Edo Berger, Jenne Driggers, Andreas Freise, Jeff Kissel,
Alex Nitz

Data Analysis: The computational cost for compact-binary searches is
manageable in Cosmic Explorer as the cost scales principally with the
bandwidth of the detector, not the overall sensitivity. Cosmic Explorer’s
increased bandwidth requires only 2-3x more computational power than Advanced
LIGO. However, there are a number of technical challenges facing compact-
binary searches that will need research and development over the coming years.
These include: power-spectral density and background estimation in the
presence of multiple signals, improved methods for accessing low-frequency
sensitivity. Searches for continuous wave signals remain the most expensive
and will require continued investment into methods to make the most of
available computing resources. The substantial data-analysis challenges are
associated with parameter measurement, given the expected signal rate. The
Cosmic Explorer challenge differs from LISA; the Cosmic Explorer data set is
much larger and signals are expected at a rate of 1/minute, and so some
overlap can be anticipated, but are generally not confusion limited. Fast
methods of parameter estimation that amortize the costs (e.g., machine
learning) or provide rapid computation of the likelihood (e.g. reduced-order
or heterodyne likelihoods) will need technical development. A significant
effort will be required to automate signal detection, parameter measurement,
and validation to cope with the high rate of signals. Extracting the science
from loud signals will require much more accurate waveform models than
currently available. Continued investment in numerical simulations and
supporting theory (especially nuclear theory for neutron star mergers) will be
essential.

Data Production, Calibration, and Delivery: A key element in achieving success
in CE era must be a paradigm shift in human resources for these corners of
operation. To date, these activities have only had support from transient
person power, and that power must shift to a sustained team of people with
permanent positions whose primary focus is on these issues. Maintaining the
highest quality data and delivering it on rapid timescales that CE needs
requires a diverse cohesive team whose knowledge base covers applied physics,
engineering, and data science as well as observational astrophysics. Transient
teams are vulnerable to institutional memory loss, lack of integration with
detector design and development, and the inability to create extensible and
automated systems upon which the detectors continual upgrades depend. In terms
of cost planning, it must be considered equal to, not mutually exclusive to,
nor redundant with, those teams covering hardware development, control design,
and noise reduction.

Data Access Models: Searches and extensive parameter estimation have already
been performed by several groups independent of the LIGO Scientific
Collaboration. These groups have demonstrated that rapid turn-around for key
science is possible. The Cosmic Explorer concept proposes a very open model
for data access, based on the way that the Rubin Telescope and NASA missions
are proceeding. There was discussion that the U.S. approach to Open Data is
different from the European approach, especially since the best science comes
from Cosmic Explorer operating jointly with Einstein Telescope. It was
identified that discussion is needed between the U.S. and E.U. partners on the
path forward for data access. A recurring theme was the incentive for
experimental scientists to invest effort in 3G if data is open. Is the current
LSC model where experimenters are generally detached from the data analysis,
but have authorship on the publications sustainable? Being one author in
O(1000) might be intellectually rewarding for the first detections, but will
that continue for the next decade? Would an open model make it easier for
instrument scientists to participate in small teams pursuing analysis projects
and allow them to be more connected to observational science? What would the
“Cosmic Explorer Lab” look like in an era of Open Data?

###  5.7 LIGO Laboratory Perspective

Presenter: David Reitze

Perspectives on current LIGO Laboratory involvement in Cosmic Explorer as well
as exploring future paths for further participation and integration with CE
were presented. The LIGO Laboratory effectively functions as the US national
laboratory for gravitational-wave detector development and observatory
operations, and is thus poised to play a foundational role in CE as it moves
forward. LIGO Laboratory staff are already playing key roles in many CE
activities, including the overall leadership of the CE Horizon Study Team and
Consortium as well as R&D programs for the CE vacuum system.

The LIGO Lab brings unique expertise in areas critical to the success of CE,
including interferometric gravitational-wave detector R&D and the management
of large-scale observatory construction projects, having successfully built
the LIGO Hanford and Livingston Observatories and the Initial and Advanced
LIGO detectors. The scale and scope of CE will require much larger levels of
participation and effort than the LIGO Laboratory can provide, however its
capabilities in key areas will be essential for CE to move forward on the
timescales envisioned in the Horizon Study. To foster the engagement of the
LIGO Lab in CE, discussions should begin soon among the CE team, the LIGO
Laboratory management team, and the NSF.

Other points covered in the presentation included:

International contributions to CE \- the Advanced LIGO Project benefited
greatly from in-kind hardware contributions from institutions in Europe and
Australia. Given CE’s much larger scale and its estimated cost, partnerships
with international institutions to lead the R&D on key CE subsystems and
deliver those subsystems will leverage CE development and construction costs
as well as demonstrate the commitment of the international community toward CE
as a pillar of the next generation ground-based gravitational-wave observatory
network. Discussions should begin soon to identify the scope and scale of
international contributions.

CE construction funding \- a major challenge going forward is the need to
greatly increase the NSF Major Research Equipment and Facilities Construction
(MREFC) funding line needed to support CE construction.While CE presents an
extremely compelling science case, the projected price tag of US$1.6B ensures
that it will be competing with several other large-scale astronomical
observatories (TMT, GMT, ngVLA) and physics experiments (CMB-S4 and IceCube
Gen2) for construction funding. Upgrades to the current LIGO 4km detectors
(incremental or e.g., for a Voyager-type cryogenic step) would also compete
for funds. Support of all of these projects (should they go forward) will
necessitate a 3X to 4X increase in the annual MREFC budget over current
levels. This will be a ‘heavy lift’, requiring sustained engagement not only
with NSF but also with the US Congress who are responsible for authorizing and
appropriating NSF’s budget. Ultimately, it may very well be the availability
of funding that limits the pace of CE.

###  5.8 LIGO Scientific Collaboration perspective

Presenter: Patrick Brady

The LIGO Scientific Collaboration remains focused on making the most effective
use of the current observatories in Hanford, WA and Livingston, LA to observe
the gravitational-wave sky. Over the past 5 years, the field has gone from the
first direct detection of gravitational waves from the merger of a pair of
black holes to a routine detection rate of once per 5 days. The most recent
data release identifies 90 signals likely to be from merging compact objects
including black holes and neutron stars. Other milestones include the first
detection of gravitational waves from a merging neutron star GW 170817, which
was also the first multi-messenger event observed in gravitational waves, the
introduction of public alerts at the beginning of the third LIGO-Virgo-KAGRA
(LVK) observing run (O3), and an early warning test at the end of O3. The LVK
has also been releasing strain data in chunks of 6 months about 18 months
after the data are acquired. The public alerts are received with great
interest by the broader astronomy community. Other gravitational-wave
scientists use these data to search for additional sources of gravitational
waves.

The success of the current generation of gravitational-wave detectors is
tightly bound with network operations to provide increased detection rates,
improved localization, and access to additional information in the
gravitational waves. LIGO-Virgo-KAGRA are discussing a new organizational
framework for collaborating on observational and instrumental science, for
jointly planning and executing observing runs, and to share common services.
The charter and governance structure of this organization, called the
International Gravitational-Wave Observatory Network (IGWN), are being
developed.

Over the next decade, the LSC plans to carry out a sequence of observing runs
with improving sensitivity. The fourth (O4) observing run will begin in
December 2022 with a binary neutron star range of 160-190 Mpc. The fifth (O5)
observing run will follow around the middle of the decade with a planned
sensitivity more than 300 Mpc. Evolution in the theoretical waveforms, the
approaches to ‘cleaning’ the data, the analysis pipelines, and the parameter
estimation will be pursued in parallel with the instrument advances. These
improvements through the O5 LVK Observing run will bring the detection rate of
compact binaries to several per day as we approach the end of the decade and
may reveal other sources of gravitational waves, such as those from pulsars or
a stochastic background of gravitational waves.

The LSC and the LIGO Lab are currently examining options for additional
instrumental upgrades to be implemented after O5 that could be installed
within the current LIGO facilities. The goal is a plan that dovetails with
Cosmic Explorer (and Einstein Telescope) construction and initial
observations. The research, development and implementation of upgrades in LIGO
(Virgo and KAGRA) can be used to demonstrate new technologies and mitigate
risk for the next generation facilities. The LSC is committed to continued
observational coverage of the gravitational-wave sky for multi-messenger
astrophysics and looks forward to detecting as yet unobserved gravitational-
wave sources.

###  5.9 National Science Foundation perspective

Presenter: Pedro Marronetti; Summarized by Shoemaker

The US National Science Foundation has been the source for all US funding of
NSF’s LIGO and for the greater ground-based gravitational-wave program in the
US. Its support continued beyond the initial construction of the Livingston
and Hanford 4km Observatories, through the major Advanced LIGO upgrade, and is
now enabling the A+ incremental upgrade. Very welcome additional support has
come from the UK, Germany, and Australia, and the worldwide R&D effort has
been crucial in developing the concepts which the Caltech/MIT LIGO Laboratory
has engineered, installed, commissioned, and operated.

The NSF funding mechanism for large projects is the Major Research Equipment
and Facilities Construction (MREFC) account, currently targeting projects of
US$70 million and greater. Initial planning and design and post-construction
operation and maintenance are supported through the Research and Related
Activities (R&RA) account. Current MREFC projects include ALMA and the Vera
Rubin Observatory.

There is a well-defined process for developing a project to the point of
readiness for MREFC funding, and subsequently through the Conceptual,
Preliminary, and Final design phases. The process is described in some detail
in the MFG.757575https://www.nsf.gov/bfa/lfo/lfo_documents.jsp To note is that
the NSF follows a policy of no additional funding after the initial MREFC
allocation; the project must be de-scoped in case of projection of overruns.
Broader impacts are considered as important core elements of Projects, and are
funded as part of the MREFC.

A rough likely timeline was given for Cosmic Explorer. With the completion of
the CE Horizon Study, the NSF can now look for community support and ‘blue
ribbon panel’ support, which could enable the NSF Director to authorize
funding for the Conceptual Design (CD) phase. The CD and Preliminary Design
phases are normally 2-3 years each; if successful, the NSF could recommend to
Congress to fund the MREFC and the 2-3 year Final Design would be launched.
The Cosmic Explorer project could take from entrance into the Design Stage to
beginning of operations from 11 to 16 years. Evidently, some steps could go
more quickly or more slowly.

An ongoing challenge for the NSF is managing the operations costs, in
particular in the Astronomy Division. LIGO is a significant operations cost
for the Physics division. The NSF may in the coming years adopt a different
approach, but in any event the accumulated cost of some decades of operation
of Cosmic Explorer is a non-negligible consideration for NSF adoption of CE.

While additional sources of funds (as an example the US Department of Energy)
for CE would ease the burden on the NSF and could raise the likelihood and/or
speed of execution of the Project, multi-agency Partnerships are complicated
to establish and lead to reporting burdens which cover all the engaged funding
agencies.

###  5.10 International Collaboration

Presenter: Rai Weiss; Summarized by Shoemaker

Previous Dawn meetings have had extended discussions on the subject of the
value of collaboration among the groups developing the next generation of
gravitational-wave observatories. The advantages are multifold:

  * •

Improved efficiency of R&D due to shared insights, and the possibility to
‘divide and conquer’ by distributing tasks across the world-wide research
groups

  * •

Developing a common observational science vision, and seeking to develop a
network which seeks an optimal use of the resources available worldwide

  * •

Growth of the scientific workforce in an environment which stimulates
exchanges and intellectual cross-pollination

  * •

Leveraging of the investments across countries and continents, ensuring the
best use of the significant funds needed to build next-generation
observatories

However, there are also difficulties. To date, the two leading projects,
Einstein Telescope and Cosmic Explorer, have been out of sync, due to the
earlier start of Einstein Telescope. ET also was conceived before the first
detections and without other GW detectors in mind; CE is designed around the
post-initial-detection environment with networking in mind. There are
reasonable concerns that the funding for projects will take different
timelines and suffer from different detours and a desire not to have all
detectors held to the slowest of the timelines. There is also a sense of
desire for independence and freedom to pursue the locally preferred solution
to any given challenge.

LIGO and Virgo have taken paths which have explored both independence and
collaboration in different domains and epochs, and certainly the advantages of
collaboration and shared effort are clear. The data analysis effort is already
very well coordinated and fully joint between LIGO and Virgo, and KAGRA is
joining that effort. A recent initiative, IGWN (for International
Gravitational-Wave Network), focuses to date on the shared LIGO-Virgo-KAGRA
computing infrastructure. The distribution of data-analysis computing tasks,
efficient handling of low-latency alerts, and management of security and
access are profiting from this joint effort.

The instrument development has been less closely coordinated to date. There is
open communication between LIGO, Virgo, and KAGRA, but the differences in
infrastructure, timelines, funding styles and constraints, and finally the
social styles of LIGO, Virgo, and KAGRA have made it such that the
collaboration has been mostly at the level of workshops and meetings rather
than substantially shared effort.

It is perfectly clear from the presentations on the observational science the
advantages of a true network of detectors with the kind of sensitivity
foreseen for the detectors planned for the next generation of observatories.
It is crucial to realize that science to have detectors which work as
synergistically as is feasible, from the perspectives of frequency range,
sensitivity, uptime, and upgrade planning. It is also crucial to make the best
possible use of the significant resources – financial and human – needed to
realize the network. Closer collaboration can help realize these imperatives.

Some suggestions for moving adiabatically to a more collaborative environment
for ET and CE were made. Starting with common modeling environments, base
models for noise sources, and exchanges of input parameters, cross-checks on
both the physics of limitations to sensitivity and on design trades will
become easy and reduce risk for both CE and ET. From this some common designs
could develop, which may be fabricated independently, or ultimately with teams
making all of a given component for ET and CE. A near term target that is
gaining momentum is joint effort on value engineering of the vacuum systems
for ET and CE, with CERN playing a role as well. Close coordination of the run
planning should be foreseen, with a group drawn from the ET and CE teams
sharing the task and authority.

Several parallel efforts seem advisable to make progress. Sharing email lists,
and giving invitations to meetings, is easy and immediately fruitful. IGWN may
provide a structure and a starting point for an organization. GWIC can ask
GWAC if there are mechanisms for complementary light-weight funding for
meetings, meeting technology, and persons who are funded to facilitate joint
effort.

A recommendation is to establish a small group of persons, representing the
entities who wish to be involved, who are charged to explore and launch
efforts along these lines of initiating coordinated activities between CE and
ET.

##  6 Realizing Designs

###  6.1 Megaprojects Round Table

Gary Sanders, discussion leader/coordinator; Participants: Anne Kinney,
Natalie Roe, Suzanne Staggs, Sidney Wolff, Jim Yeck

The megaprojects panel includes experts from other fields of physical science
as well as leaders of large projects in astronomy, astrophysics, cosmology,
particle and nuclear physics. These experts have led in projects with private
support as well as projects sponsored by NSF, NASA, DOE and European public
agencies, and national and global in membership. Informed by the very
comprehensive Cosmic Explorer Horizon Study and the preceding discussions in
the workshop, the panelists provided a number of important perspectives and
useful guidance going forward.

The goals for the panel were to suggest a roadmap and the next concrete steps
for Cosmic Explorer. Key to these would be the organizational structure for
the design phase and its evolution to the construction and operations phase.
The current Horizon Study is led by a university group. While it represents an
excellent step, the CE project is seen as a $2 billion USD (2030 $) project
that will require, beyond the financial resources, strong institutional
capabilities and robust governance. It was felt that the design phase of the
project should urgently set an organization in place that represents a step on
a path to the ultimate appropriate robust organization. Financial,
institutional and intellectual resources needed suggest models that may
involve the LIGO Laboratory, management and operating contractors of the type
currently acting for NSF, national laboratories or new corporations. The
roadmap should define a clear trajectory to develop, establish and exercise
appropriate governance.

A driver of the project will be selection of the site. This process should be
carried out so that it has completed the requirements, solicitation, proposal
reviews and basis for selection by the end of the design phase. Demonstration
of compliance with environmental and historical preservation regulations as
well as cultural public participation processes should be at the decision
stage. However, it is well recognized that true engagement with the local
candidate communities will be critical and this must start at the earliest
possible time; it does not suffice simply to have legal clearance to proceed.
The project’s presence and face must engage and partner with local communities
to facilitate CE as a joint proposal of the original proponents and the host
communities. This is a daunting challenge but needed to lay the foundation for
a successful CE project. This theme was well understood and discussed by the
proponents and the panel alike. It was referred to as “integration” with the
host community.

The combination of defining the governance and the collaboration with the host
communities (we assume 2 communities for 2 sites) defines “who” CE is. This is
key.

The panelists described these processes for prior large projects. Based upon
projects like ALMA, SKA, and TMT, this process takes a decade.

Local communities are not monoliths. Host community residents and local
indigenous peoples may represent distinct local groups who must be engaged.
But these groups are likely not monolithic as well and engagement, opposition,
acceptance and consent may be quite varied among these multiple groups. The
complexity and centrality of interactions between the CE project and the host
communities must be addressed by genuine presence and sincere close
engagement.

Though the legal processes such as environmental impact statements and
cultural consultations may lead to legal approval of CE, these are not
substitutes for the intimate engagement described above. However, the
leadership and involvement of the government agencies in these public
participation processes has been found to add gravitas and trust to
commitments made to host communities.

It was felt that the CE design stage should move early to a baseline
configuration and fully develop that design rather than continuing the trade
studies of potential design options. A fully developed baseline design,
complete with system engineering, scope definition, risk management and
reliable cost and schedule studies is a superior point of departure for any
design variations that may develop out of necessity, such as budget ceilings
from sponsors.

Given the size of the project, while a lead agency such as NSF may dominate in
support, multiple agencies and partners may be needed to accomplish a project
of the scale and complexity of CE. Private funding, given its agility, may be
very helpful in getting the design stage off to a timely start.

DOE laboratories possess key skills in civil construction and high vacuum
technology, cost drivers for CE. DOE laboratories should be engaged but not as
service organizations in these critical skills. The science reach of CE covers
many key thrusts in the DOE high-energy, nuclear and particle astrophysics
realms. The CE community should be out giving talks and continuing their
participation in the Snowmass process.

CE will drive NSF to consider the needed budget size, growing NSF
capabilities. Community engagement should extend beyond host community
integration to include partners such as Historically Black Colleges and
Universities and other communities for whom CE may leverage participation
these sciences.

LIGO has shown that it can generate a steady influx of the brightest young
people. CE can be a catalyst for frontier activity and involvement at
universities. University involvement generates diversity as well as novelty
and influence in other fields. And a careful look at university engagement in
LIGO shows that it created many of the key successes of LIGO.

As NSF is likely the lead sponsor, lessons can be learned beyond LIGO, from
the history of the astronomy observatories. Site selection, host community
support and opposition including legal challenges, managing organizations with
experience and trust with the NSF; these are aspects to be carefully
considered.

The panel felt that, with these issues in mind, CE should move out promptly.

###  6.2 Recommendations and Conclusions

Presenter: Dave Reitze

A high level overview of the workshop themes was presented to the participants
at the Dawn VI close out, followed by a moderated discussion among the
participants. Participants felt that the CE science case was strong and well
supported in the Horizon Study. Most of the science goals are robust against
discoveries that may occur with the current generation of detectors. Surveying
the ‘heavy’ mass spectrum of black holes (with masses greater than a few
hundred solar masses) is one such example.

Care will be needed to make a clear and compelling case for a standalone CE,
while noting the added gains and discovery science that come with partnering
with ET.

Although it is clear that the CE science case is strong, the science case is a
necessary but not sufficient condition to enable CE to move forward toward
securing funding, being constructed, and into operations. As noted in Dawn VI
presentations and discussions, the complexity and scale of the project in
terms of infrastructure, site selection and acquisition, cost, and needed
human resources is such that there will be many paths by which CE could be
delayed or, much worse, fail to be built.

Some recommendations can be enunciated:

  * •

A very significant upgrade to the current LIGO observatories may well delay
the start of funding of CE.

  * •

It is important to communicate clearly that some key CE science targets rely
wholly or partially on GW-enabled multi-messenger astronomy – thus requiring a
three-site GW observatory network for optimal source localization. While CE
and ET collectively make up three-site network each science case must ‘stand
on its own’ to secure construction funding as there is no guarantee that both
will be operational.

  * •

Drawing lessons learned by studying other projects of similar scales will
prove valuable for the CE Project as it scales up.

  * •

In the near term, there is a strong desire from the broad community that the
present detectors continue to observe until CE and ET are available.

  * •

GW facilities should give a “mission statement” level of support (if not an
absolute guarantee) to seek to continue operations during the main mission
lifetimes of space missions dedicated to GW follow-up. This requires a rough
5-10 year horizon for the planning of instrument operation, to match the time
scale for space missions.

  * •

In the near term, incremental deepening of the collaboration between ET and CE
is to the advantage of all parties. Point persons in ET and CE should be named
to bring this to fruition.

Summarizing the two main conclusions from the meeting:

  * •

The science opportunities afforded by CE and ET are broad and compelling,
impacting a wide range of disciplines in physics and high energy astrophysics.

  * •

A strong endorsement of Cosmic Explorer, as described in the CE Horizon Study,
is a primary outcome of DAWN VI.

##  Appendix A Contributors to and endorsers of this report

Naresh Adhikari |  University of Wisconsin Milwaukee
---|---
Odylio Aguiar |  Instituto Nacional de Pesquisas Espaciais
Ryan Andersen |  Univ. California, Riverside
M. Celeste Artale |  University of Padua
K. G. Arun |  Chennai Mathematical Institute
Stefan W. Ballmer |  Syracuse University
Enrico Barausse |  SISSA (Trieste, Italy)
Barry Barish |  Caltech/LIGO and UCR
Lisa Barsotti |  MIT
Matteo Barsuglia |  CNRS - APC
Willke Benno |  Leibniz University Hanover
Beverly Berger |  Stanford
Edo Berger |  Harvard
Emanuele Berti |  JHU
GariLynn Billingsley |  California Institute of Technology
Ofek Birnholtz |  Bar-Ilan University
Sebastien Biscans |  Caltech and MIT
Sylvia Biscoveanu |  MIT
Marie Anne Bizouard |  CNRS - Observatoire de la Cote d’Azur
Alexey Bobrick |  Technion Institute
Sukanta Bose |  IUCAA and Washington State University
Patrick Brady |  University of Wisconsin-Milwaukee
Marica Branchesi |  Gran Sasso Science Institute
Jim Brau |  University of Oregon
Floor Broekgaarden |  Center for Astrophysics - Harvard & Smithsonian
Duncan Brown |  Syracuse University
Daniel Brown |  University of Adelaide
Tomasz Bulik |  University of Warsaw
Alessandra Buonanno |  Max Planck Institute for Gravitational Physics, Potsdam
Laura Cadonati |  Georgia Tech
Elenna Capote |  Syracuse University
Marco Cavaglia |  Missouri S&T
Poonam Chandra |  National Centre for Radio Astrophysics, TIFR, India
Hsin-Yu Chen |  Massachusetts Institute of Technology
Xu Chen |  University of Western Australia
Giacomo Ciani |  University of Padova
Alessandra Corsi |  Texas Tech University
Michael Coughlin |  UMN
David Coulter |  University of California, Santa Cruz
Jolien Creighton |  University of Wisconsin–Milwaukee
Alexander Criswell |  University of Minnesota Twin Cities
Alan Cumming |  University of Glasgow, UK
Kristen Dage |  McGill University
Stefan Danilishin |  Maastricht University/Nikhef, the Netherlands
Saurya Das |  University of Lethbridge
Derek Davis |  Caltech
Nicholas Demos |  MIT
Riccardo DeSalvo |  Ric-lab LLC
Mariano Dominguez |  Universidad Nacional de Cordoba
Daniela Doneva |  University of Tuebingen
Bruce Edelman |  University of Oregon
Anamaria Effler |  Caltech, Pasadena, CA
Matthew Evans |  MIT
Jose María Ezquiaga |  University of Chicago
Stephen Fairhurst |  Cardiff University
Ke Fang |  University of Wisconsin-Milwaukee
Maxime Fays |  ULiège
Svenja Fleischer |  Western Washington University
Wen-fai Fong |  CIERA, Northwestern University
Giacomo Fragione |  Northwestern University
Raymond Frey |  University of Oregon
Josh Frieman |  Fermilab
Peter Fritschel |  M.I.T.
Chris Fryer |  LANL
Hannah Gallagher |  RIT
Gianluca Gemme |  INFN Sezione di Genova
Andrew Gendre |  OzGrav-UWA
Andrew Geraci |  Northwestern University
Priyanka Giri |  INFN Pisa
Amy Gleckl |  California State University Fullerton
Gabriela Gonzalez |  Louisiana State University
Aniello Grado |  INAF
Alexandra Gruson |  California State University Fullerton
Anuradha Gupta |  University of Mississippi
Evan Hall |  Massachusetts Institute of Technology
Sophia Han |  UC Berkeley/INT, U Washington
Mark Hannam |  Cardiff University
Jan Harms |  Gran Sasso Science Institute
Gregory Harry |  American University
Carl-Johan Haster |  Massachusetts Institute of Technology
Jack Heinzel |  MIT
Jackie Hewitt |  MIT
Daniel Holz |  UChicago
Chuck Horowitz |  Indiana University
Jim Hough |  University of Glasgow, UK
Panagiotis Iosif |  Aristotle University of Thessaloniki
Bala Iyer |  ICTS-TIFR, Bangalore
Wenxuan Jia |  MIT
Nathan Johnson-McDaniel |  University of Mississippi
Li Ju |  University of Western Australia
Vicky Kalogera |  Northwestern University
Jonah Kanner |  Caltech
Mansi Kasliwal |  Caltech
Stavros Katsanevas |  European Gravitational Observatory
Erik Katsavounidis |  Massachusetts Institute of Technology
Keita Kawabe |  LIGO Hanford Observatory
Joey Shapiro Key |  University of Washington Bothell
Jeffrey Kissel |  LIGO Hanford Observatory
Kostas Kokkotas |  University of Tuebingen
Antonios Kontos |  Bard College
Mikhail Korobko |  University of Hamburg, Germany
Kevin Kuns |  MIT
Arjun Kurur |  Indian Institute of Technology, Madras
Harald Lück |  Leibniz Universität Hannover
Adele La Rana |  INFN - Rome 1 & University of Verona
Philippe Landry |  Canadian Institute for Theoretical Astrophysics
Michael Landry |  Caltech - LIGO Hanford Observatory
Brian Lantz |  Stanford University
Paul Lasky |  Monash University
Albert Lazzarini |  California Institute of Technology
Hyung Won Lee |  Inje University, Korea
Hyung Mok Lee |  Seoul National University
Luis Lehner |  Perimeter Institute
Giovanni Losurdo |  INFN - Pisa
Hudson Loughlin |  MIT
Geoffrey Lovelace |  Cal State Fullerton
Ronaldas Macas |  University of Portsmouth
Lorena Magaña Zertuche |  University of Mississippi
Michele Maggiore |  Université de Genève
Vuk Mandic |  University of Minnesota Twin Cities
Szabolcs Marka |  Columbia University in the City of New York
Zsuzsa Marka |  Columbia Astrophysics Laboratory
Rodica Martin |  Montclair State University
Daniel Martinez |  CSU fulelrton
Kenneth Mason |  Massachusetts Institute of Technology
Nergis Mavalvala |  Massachusetts Institute of Technology
David McClelland |  The Australian National University
Lee McCuller |  California Institute of Technology
Kara Merfeld |  University of Oregon
Yuta Michimura |  University of Tokyo
Cole Miller |  UMd
Edoardo Milotti |  University of Trieste and INFN-Sezione di Trieste - Italy
Guenakh Mitselmakher |  University of Florida
Richard Mittleman |  MIT
Marlo Morales |  California State University, Fullerton
Ewald Mueller |  Max-Planck-Institute for Astrophysics
Suvodip Mukherjee |  Perimeter Institute
Arunava Mukherjee |  Saha Institute of Nuclear Physics
Rohit Nair |  Model College
Lan Quynh Nguyen |  University of Notre Dame
Alexander Nitz |  Max Planck Institute for Gravitational Physics, Hannover
Benjamin Owen |  Texas Tech University
Archana Pai |  Indian Institute of Technology Bombay<EMAIL_ADDRESS>
Oli Patane |  California State University Fullerton
Hiranya Peiris |  University College London / Stockholm University
M.E.S Pereira |  Universität Hamburg
Harald Pfeiffer |  Max Planck Institute for Gravitational Physics, Potsdam
Jorge Piekarewicz |  Florida State University
Michele Punturo |  INFN Perugia
Frederick Raab |  California Institute of Technology
Jocelyn Read |  California State University, Fullerton
Stuart Reid |  University of Strathclyde
Dave Reitze |  Caltech
Michael Rezac |  Cal State-Fullerton
Fulvio Ricci |  INFN Sezione di Roma
Jonathan Richardson |  University of California, Riverside
Keith Riles |  University of Michigan
Jameson Rollins |  LIGO Caltech
Michael Ross |  University of Washington
Surabhi Sachdev |  UWM
Mairi Sakellariadou |  King’s College London
Gary H. Sanders |  Simons Observatory, Center for Astrophysics and Space Sciences, UC San Diego
Misao Sasaki |  University of Tokyo
Bangalore Sathyaprakash |  Penn State and Cardiff University
Richard Savage |  LIGO Hanford Observatory
Robert Schofield |  University of Oregon
Audrey P. Scott |  University of Chicago
Olga Sergijenko |  Taras Shevchenko National University of Kyiv & MAO NASU
Lijing Shao |  Peking University
Peter Shawhan |  University of Maryland
Deirdre Shoemaker |  University of Texas at Austin
David Shoemaker |  MIT
Vasileios Skliris |  Cardiff University
Joshua Smith |  California State University, Fullerton
Frank Soboczenski |  King’s College London
Varun Srivastava |  Syracuse University
Andrew Steiner |  University of Tennessee, Knoxville & Oak Ridge National Laboratory
Sebastian Steinlechner |  Maastricht University, the Netherlands
Riccardo Sturani |  International Institute of Physics, Natal (Brazil)
Shreevathsa Chalathadka Subrahmanya |  University of Hamburg
Ling Sun |  The Australian National University
Patrick Sutton |  Cardiff University
Satoshi Tanioka |  Syracuse University
David Tanner |  University of Florida
Christina Thöne |  IAA - CSIC
Eleonora Troja |  University of Rome Tor Vergata
Rhondale Tso |  Caltech
Elias C. Vagenas |  Kuwait University
Gabriele Vajente |  Caltech
Jo van den Brand |  Nikhef and Maastricht University
Peter Veitch |  OzGrav-Adelaide
Subham Vidyant |  Syracuse University
Salvatore Vitale |  MIT
Alan Weinstein |  California Institute of Technology
Chris Whittle |  Massachusetts Institute of Technology
Helvi Witek |  University of Illinois Urbana-Champaign
Victoria Xu |  MIT
Huan Yang |  Guelph University
Stoytcho Yazadjiev |  University of Sofia
Nicolas Yunes |  UIUC
Liyuan Zhang |  California Institute of Technology
Aaron Zimmerman |  University of Texas at Austin
Michael Zucker |  Caltech and MIT