Invited Speakers
Katie Breivik, CCA, Flatiron
Title: Multiband Gravitational Wave Populations as a Piece of the Compact Object Formation Puzzle
Abstract: The observation of gravitational waves from 47 pairs of merging black hole and neutron star binaries by the LIGO-Virgo Collaboration offers the first glimpse of the potential to use these populations as tools to study the formation of compact objects. However, even with 44 mergers, the dominant formation pathways for merging binary black holes remain unconfirmed. Furthermore, even with third generation ground-based detectors, which could discover merging binary black holes across all redshifts, such mergers only account for a tiny fraction of all black holes formed in the Universe. In this talk I will discuss opportunities to probe the formation environments and scenarios of compact objects using observations from ground- and space-based GW detectors with a particular focus on the complementary source information each detector provides. I will also discuss how GW populations play a role in the larger landscape of observations of compact objects in binaries.
Paola Buitrago, PSC
Title: A High Performance AI+HPC Ecosystem for Science and Discovery at the Pittsburgh Supercomputing Center
Abstract: Artificial intelligence (AI) is transforming research through analysis of massive datasets and accelerating simulations by factors of up to a billion. Such acceleration eclipses the speedups that were made possible through improvements in CPU process and design and other kinds of algorithmic advances. It sets the stage for a new era of discovery in which previously intractable challenges will become surmountable. To succeed, the research community requires a high-performance computational ecosystem that seamlessly and efficiently brings together scalable AI, general-purpose computing, and large-scale data management. The Pittsburgh Supercomputing Center (PSC) offers a second-generation computational ecosystem to enable AI-enabled research, bringing together carefully designed systems and groundbreaking technologies to provide at no cost a uniquely capable platform to the research community. It consists of two major systems: Neocortex and Bridges-2. Neocortex embodies a revolutionary processor architecture to vastly shorten the time required for deep learning training, foster greater integration of artificial deep learning with scientific workflows, and accelerate graph analytics. Bridges-2 integrates additional scalable AI, high-performance computing (HPC), and high-performance parallel file systems for simulation, data pre- and post-processing, visualization, and Big Data as a Service. Neocortex and Bridges-2 are integrated to form a tightly coupled and highly flexible ecosystem for AI- and data-driven research.
Deep Chatterjee, UIUC, NCSA
Title: Challenges in Electromagnetic Follow-Up of Gravitational-Wave Transients
Abstract: It has been almost 4 years since the observation of gravitational waves (GWs) from the first binary neutron star (BNS) merger, GW170817, and its panchromatic observation in gamma-rays and the electromagnetic (EM) spectrum. The event marked the dawn of multi-messenger EMGW astronomy, but it has been the sole success story even after the LIGO/Virgo third observing (O3) run, which reported 56 public GW discoveries. Although interesting candidates were reported, and some received intense follow-up, no associated counterparts were observed. This shows the challenge faced by EMGW observations - the needle in a haystack nature of the problem. The first step towards discovery is the development of rapid communication infrastructure between partner facilities, and data-products that aid in the follow-up. I will talk about the efforts from the LIGO/Virgo third observing run. I will also highlight some of the tools being developed for the future success of multi-messenger astronomy, including the role of alert brokers in the next generation of telescope facilities.
Hsin-Yu Chen, MIT
Title: Prospects for Standard-Siren Cosmology with Future Gravitational-Wave Observations
Abstract: The joint observation of binary neutron star inspiral GW170817 and kilonova AT 2017gfo allowed for the measurement of Hubble constant with gravitational waves for the first time. In this talk, I will summarize the current status and challenges of gravitational-wave cosmological measurements, and discuss our expectations for future developments.
Daniel D'Orazio, NBI
Title: Multi-messenger and Multi-band Adventures in Lensing
Abstract: I will demonstrate how repeated gravitational lensing of light and gravitational waves can be used as a probe of the environment and formation of stellar-mass compact-object binaries. Gravitational self-lensing in an electromagnetically bright binary can provide unique electromagnetic signatures of these systems just prior to their entering the LISA band, possibly overlapping LISA's low frequency end. Gravitational waves from binary black hole mergers occurring around supermassive black holes in galactic nuclei can exhibit an imprint of the binary's orbit around the supermassive black hole due to the orbital Doppler boost and to lensing of gravitational waves by the supermassive black hole. Such repeated lensing of gravitational waves would be most prominent in the LISA to Deci-hertz bands and provide strong evidence for a binary's origin even before its merger in the LIGO band.
Anuradha Gupta, Mississippi
Title: Rigorous Tests of General Relativity with Multiband Gravitational-Wave Observations
Abstract: A null-test of general relativity (GR) would be possible in the future by synergistically combining stellar-mass binary black hole signals observed in the third-generation ground-based detectors such as Cosmic Explorer and Einstein Telescope and space-based detectors such as LISA. I will discuss how a population of binary black hole mergers would permit us to constrain all the known physical effects in GR to the precision of a few percent. Such tests would play a pivotal role in constraining modified theories of gravity beyond GR in the future.
Leïla Haegel, APC Paris
Title: How Machine Learning can Enhance Gravitational-Wave Physics
Abstract: Machine learning algorithms have emerged as a powerful approach to study gravitational waves by virtue of their ability to characterise low-amplitude signals, infer in high dimensional systems and analyse large datasets. They are foreseen to become a cornerstone of the field as new ground and space-based interferometers will detect novel populations of astrophysical sources. This talk reviews current applications of neural networks and other novel algorithms for the analysis of gravitational-waves data, including fast measurements of the astrophysical parameters of gravitational-wave sources, algorithms for reduction and characterisation of non-astrophysical detector noise, and applications to gravitational waveforms modelling. I will also mention the potentiality and challenges of such techniques for future facilities.
Karan Jani, Vanderbilt
Title: Intermediate-Mass Black Hole Hunt from Earth, Space & Moon
Abstract: The latest LIGO-Virgo data confirms a previously unknown population of “lite” intermediate-mass black holes (IMBHs) of about 100 solar mass. This is just the tip of the iceberg, and, in this talk, I will argue why IMBHs (100-100,000 solar masses) are the most exciting sources in multi-band, multi-messenger astronomy for the foreseeable future. In doing so, I will review the detection landscape of IMBHs for several experimental frontiers: large space missions, cube-sats, lunar landers, and next avatars of LIGO. I will briefly highlight some new astrophysical and cosmological insights we have gained with the IMBH search in LIGO.
Tim Kovachy, Northwestern
Title: Exploring Gravitational Physics with the MAGIS-100 Atom Interferometer
Abstract: Atom interferometers exploit spatially delocalized quantum states to make a wide variety of highly precise measurements. Recent technological advances have opened a path for atom interferometers to contribute to multiple areas at the forefront of modern physics, including searches for wave-like dark matter, gravitational wave detection, and fundamental quantum science. MAGIS-100 is a 100-meter-tall atom interferometer being built at Fermilab to pursue these directions. MAGIS-100 will serve as a prototype gravitational wave detector in the midband frequency range, search for wave-like dark matter, probe quantum mechanics in a new regime in which massive particles are delocalized over macroscopic scales in distance and time, and act as a testbed for advanced quantum sensing techniques. This talk will focus on the operating principles of and enabling technologies for MAGIS-100, as well as the prospects and motivation for atomic gravitational wave detectors.
Rob Plunkett, Fermilab
Title: Status of MAGIS-100: 100-Meter Atom Interferometry at Fermilab
Abstract: MAGIS-100 is an experiment to utilize the sensitivity provided by using atomic techniques from the clock and interferometry communities, implemented on a 100m vertical scale at Fermilab. This University-National Laboratory consortium will enable record-breaking quantum science, world-leading searches for ultra-light dark matter, and path-breaking demonstration of technology needed for gravitational wave detectors sensitive to frequencies in the area of 0.3 - 3 Hz. The focus of this talk will be on the implementation status of the experiment at Fermilab effort with special emphasis on the needs of this kind of detector at large scales, and on capabilities for detection of ultra-light dark matter and exotic forces.
Ira Rothstein, CMU
Title: Improving Analytic Template Building Using New Field Theoretic Techniques
Abstract: In this talk, I will review recent progress in high accuracy analytic calculations of waveforms using modern ideas in effective field theory. I will discuss the prospects for reaching sufficient accuracy to extract finite size tidal effects from the data.
Johan Samsing, NBI
Title: Decihertz Sources Originating from Dense Clusters
Abstract: I will argue why a decihertz detector will be extremely useful for probing the origin of binary black hole mergers and their underlying astrophysical environment. For this I will present specific examples derived from dense stellar clusters. Besides a simple argument for why LIGO and LISA will not be able to fully capture the astrophysical information of mergers assembled in clusters, I will present new results related to GW-form phase-shifts that will take place in the deci-hertz band. This will open up for constraining the underlying assembly mechanism of individual mergers without invoking any statistical methods together with a large merger sample.
Helvi Witek, UIUC
Title: Testing Strong-Field Gravity with Gravitational Waves
Abstract: Observations and theoretical considerations indicate that general relativity, our elegant standard model of gravity, may require modifications at cosmological or high energy scales. Candidate theories of quantum gravity, in their low-energy limit, typically predict couplings to additional fields or involve higher curvature terms. At the same time, the breakthrough discovery of gravitational waves has provided a new channel to probe gravity in its most extreme, strong-field regime. To facilitate tests of the nonlinear regime of gravity that unfolds during the collision of compact objects we require numerical relativity simulations of their late inspiral and merger. In this talk I will give a status update of numerical relativity beyond GR, its modelling challenges and future directions.