Sciences and Exploration Directorate

Bernard Joseph Kelly (he/his)

(RESEARCH SCIENTIST)

 bernard.j.kelly@nasa.gov

 301.286.7243

Org Code: 663

NASA/GSFC
Mail Code: 663
Greenbelt, MD 20771

Employer: UNIVERSITY OF MARYLAND BALTIMORE CO

Brief Bio


Bernard studied Experimental and Mathematcal Physics at University College, Dublin. After a two-year break as a financial mathematician, he attended graduate school in Penn State University, studying numerical relativity under Dr Pablo Laguna (now in Georgia Tech), graduating with a Ph.D. in 2004.

From 2004 to 2006, Bernard was a postdoctoral scholar in the University of Texas, Brownsville, working with Manuela Campanelli, Carlos Lousto, and Yosef Zlochower (now at the Rochester Institiute of Technology). Bernard's research centered on the Lazarus Project, an effort to extend then-short-lived black-hole-binary merger simulations by mapping their later stages to a more stable perturbative code.

In late 2006, Bernard came to NASA Goddard as an NPP with the Gravitational Astrophysics Laboratory, working with Joan Centrella, John Baker, and the numerical relativity group there. He continues to work at GSFC, as a CRESST Assistant Research Scientist affiliated with the Center for Space Sciences and Technology at the University of Maryland, Baltimore County.

Research Interests


Mergers of black-hole binaries in astrophysical environments.

Astrophysics: Theory & Modeling

Black holes produce no electromagnetic radiation, by definition. However, astrophysical black holes will typically live in the vicinity of considerable amounts of free baryonic matter threaded by magnetic fields, often in the form of accretion disks. The interaction of black holes with this matter can potentially lead to observable electromagnetic signals, with characteristic changes around the time of merger.

I simulate the merger of black holes in plasma environments to try to establish robust predictions for these signals, which can be seen by different ground-based and space-based telescopes, at the same time that gravitational-wave observatories (such as LIGO, or the planned ESA-led LISA mission) "hear" the black-hole merger itself.

These simulations require solving the complete set of Einstein's equations of general relativity in 3D, along with the equations of ideal magnetohydrodynamics (MHD).


Implicit-Rotating Source Gravitational-Wave Templates

Astrophysics: Gravitational Waves

The late-merger and ringdown portion of black-hole-binary coalescence is brief, but extremely powerful. It also yields the hardest-to-model segment of the continuous gravitational-wave emission, where post-Newtonian theory breaks down and the linear ringdown regime is not yet applicable. Accurate modeling of this regime requires the solution of the full nonlinear Einstein Equations of General Relativity using supercomputers. As such simulations are expensive, and the binary configuration space so large, we must synthesize the results of intelligently chosen configurations to form template banks.

Existing template banks concentrate mostly on the long-lasting inspiral segment of BH coalescences, either neglecting the merger, or treating it in an approximate way that may neglect important nonlinear processes. Using the observed link between the dominant (quadrupole) and leading sub-dominant angular modes from BH mergers, we have proposed a simple "implicit rotating source" (IRS) picture of the binary that holds through late inspiral and merger, and suggests a simple but powerful way to encode important nonlinear features of the merger waveform modes.


Characterizing Strong-Gravity Regions of Spacetime

Astrophysics: Black Holes

As the leading classical theory of gravity, general relativity is used for precision measurements of planetary, stellar, and galactic motion, and has given rise to extraordinary predictions of now-observed phenomena such as black holes and gravitational waves. Most cutting-edge computational treatments of the "strong gravity" regions of spacetimes -- e.g. the remnant after the merger of two neutron stars or smaller black holes -- require a multi-code, multi-platform approach to capture the important physics of the event, passing off data from one code to another. Very often, the simulation codes on each side of this data exchange model the black-hole spacetime very differently (e.g. the horizon might be a simple coordinate sphere r = M in one code, but a distorted spheroid in the other). It is vital that we develop more robust ways of mapping one spacetime to another to ensure that all field quantities are correctly interpreted, so that self-consistent predictions can be made for potential observable signals.

I've been working to solve this problem with Weyl curvature invariants based on the Newman-Penrose formalism. These are scalar fields with well-understood values in Kerr spacetimes, with simple dependencies on Kerrr-Boyer-Lindquist (KBL) coordinates. By calculating them for numerically evolved spacetimes, we can develop a dictionary between numerical coordinates and KBL, allowing the correct mapping of other fields from one code to the other.

Current Projects


Physics of the Cosmos science support

Technology & Missions

Coordination between NASA HQ and scientists for the Physics of the Cosmos (PhysCOS) program, organization and oversight of activities for scientific meetings (e.g., American Astronomical Society, American Physical Society, etc.), and coordinating and managing outreach related to PhysCOS (i.e., preparing publications, brochures, maintaining and updating the website).

Positions/Employment


CRESST Assistant Research Scientist

University of Maryland Baltimore County - 1000 Hilltop Circle, Baltimore, MD 21250

October 2015 - Present


CRESST Research Associate

University of Maryland Baltimore County - NASA Goddard Space Flight Center

September 2009 - October 2015


NASA Postdoctoral Fellow

Oak Ridge Associated Universities - NASA Goddard Space Flight Center

September 2006 - August 2009


Postdoctoral Researcher

Dept of Physics and Astronomy, University of Texas at Brownsville - 80 Fort Brown, Brownsville TX 78520

September 2004 - August 2006

Education


  • B. Sc. in Experimental Physics and Mathematical Physics (1995) University College, Dublin
  • M. Sc. in Mathematical Physics (1996) University College, Dublin
  • Ph. D. in Physics (2004) Pennsylvania State University

Professional Service


Refereeing

  • Referee for Physical Review D, Physical Review Letters, Classical and Quantum Gravity
  • 2016 Reviewer of the Year, Classical and Quantum Gravity
  • Member of Classical and Quantum Gravity Advisory Panel (Jan 2018 - Jan 2020)

Publications


Refereed

Werneck, L. R., Z. B. Etienne, A. Murguia-Berthier, et al. R. Haas, F. Cipolletta, S. C. Noble, L. Ennoggi, F. G. Lopez Armengol, B. Giacomazzo, T. Assumpção, J. Faber, T. Gupte, B. J. Kelly, and J. H. Krolik. 2023. Addition of tabulated equation of state and neutrino leakage support to illinoisgrmhd Physical Review D 107 (4): 044037 [10.1103/physrevd.107.044037]

Lopez Armengol, F. G., Z. B. Etienne, S. C. Noble, et al. B. J. Kelly, L. R. Werneck, B. Drachler, M. Campanelli, F. Cipolletta, Y. Zlochower, A. Murguia-Berthier, L. Ennoggi, M. Avara, R. Ciolfi, J. Faber, G. Fiacco, B. Giacomazzo, T. Gupte, T. Ha, J. H. Krolik, V. Mewes, R. O’Shaughnessy, J. M. Rueda-Becerril, and J. Schnittman. 2022. Handing off the outcome of binary neutron star mergers for accurate and long-term postmerger simulations Physical Review D 106 (8): 083015 [10.1103/physrevd.106.083015]

Murguia-Berthier, A., S. C. Noble, L. F. Roberts, et al. E. Ramirez-Ruiz, L. R. Werneck, M. Kolacki, Z. B. Etienne, M. Avara, M. Campanelli, R. Ciolfi, F. Cipolletta, B. Drachler, L. Ennoggi, J. Faber, G. Fiacco, B. Giacomazzo, T. Gupte, T. Ha, B. J. Kelly, J. H. Krolik, F. G. Lopez Armengol, B. Margalit, T. Moon, J. D. Schnittman, R. O'Shaughnessy, J. M. Rueda-Becerril, Y. Zenati, and Y. Zlochower. 2021. HARM3D+NUC: A new method for simulating the post-merger phase of binary neutron star mergers with GRMHD, tabulated EOS and neutrino leakage Astrophysical Journal 919 (2): 95-110 [10.3847/1538-4357/ac1119]

Kelly, B. J., Z. B. Etienne, J. Golomb, et al. J. D. Schnittman, J. G. Baker, S. C. Noble, and G. Ryan. 2021. Electromagnetic emission from a binary black hole merger remnant in plasma: Field alignment and plasma temperature Physical Review D 103 (6): 063039 [10.1103/physrevd.103.063039]

Porth, O., K. Chatterjee, R. Narayan, et al. C. F. Gammie, Y. Mizuno, P. Anninos, J. G. Baker, M. Bugli, C.-K. Chan, J. Davelaar, L. D. Zanna, Z. B. Etienne, P. C. Fragile, B. J. Kelly, M. Liska, S. Markoff, J. C. McKinney, B. Mishra, S. C. Noble, H. Olivares, B. Prather, L. Rezzolla, B. R. Ryan, J. M. Stone, N. Tomei, C. J. White, Z. Younsi, K. Akiyama, A. Alberdi, W. Alef, K. Asada, R. Azulay, A.-K. Baczko, D. Ball, M. Baloković, J. Barrett, D. Bintley, L. Blackburn, W. Boland, K. L. Bouman, G. C. Bower, M. Bremer, C. D. Brinkerink, R. Brissenden, S. Britzen, A. E. Broderick, D. Broguiere, T. Bronzwaer, D.-Y. Byun, J. E. Carlstrom, A. Chael, S. Chatterjee, M.-T. Chen, Y. Chen, I. Cho, P. Christian, J. E. Conway, J. M. Cordes, G. B. Crew, Y. Cui, M. De Laurentis, R. Deane, J. Dempsey, G. Desvignes, S. S. Doeleman, R. P. Eatough, H. Falcke, V. L. Fish, E. Fomalont, R. Fraga-Encinas, B. Freeman, P. Friberg, C. M. Fromm, J. L. Gómez, P. Galison, R. García, O. Gentaz, B. Georgiev, C. Goddi, R. Gold, M. Gu, M. Gurwell, K. Hada, M. H. Hecht, R. Hesper, L. C. Ho, P. Ho, M. Honma, C.-W. L. Huang, L. Huang, D. H. Hughes, S. Ikeda, M. Inoue, S. Issaoun, D. J. James, B. T. Jannuzi, M. Janssen, B. Jeter, W. Jiang, M. D. Johnson, S. Jorstad, T. Jung, M. Karami, R. Karuppusamy, T. Kawashima, G. K. Keating, M. Kettenis, J.-Y. Kim, J. Kim, J. Kim, M. Kino, J. Y. Koay, P. M. Koch, S. Koyama, M. Kramer, C. Kramer, T. P. Krichbaum, C.-Y. Kuo, T. R. Lauer, S.-S. Lee, Y.-R. Li, Z. Li, M. Lindqvist, K. Liu, E. Liuzzo, W.-P. Lo, A. P. Lobanov, L. Loinard, C. Lonsdale, R.-S. Lu, N. R. MacDonald, J. Mao, D. P. Marrone, A. P. Marscher, I. Martí-Vidal, S. Matsushita, L. D. Matthews, L. Medeiros, K. M. Menten, I. Mizuno, J. M. Moran, K. Moriyama, M. Moscibrodzka, C. Müller, H. Nagai, N. M. Nagar, M. Nakamura, G. Narayanan, I. Natarajan, R. Neri, C. Ni, A. Noutsos, H. Okino, T. Oyama, F. Özel, D. C. Palumbo, N. Patel, U.-L. Pen, D. W. Pesce, V. Piétu, R. Plambeck, A. PopStefanija, J. A. Preciado-López, D. Psaltis, H.-Y. Pu, V. Ramakrishnan, R. Rao, M. G. Rawlings, A. W. Raymond, B. Ripperda, F. Roelofs, A. Rogers, E. Ros, M. Rose, A. Roshanineshat, H. Rottmann, A. L. Roy, C. Ruszczyk, K. L. Rygl, S. Sánchez, D. Sánchez-Arguelles, M. Sasada, T. Savolainen, F. P. Schloerb, K.-F. Schuster, L. Shao, Z. Shen, D. Small, B. W. Sohn, J. SooHoo, F. Tazaki, P. Tiede, R. P. Tilanus, M. Titus, K. Toma, P. Torne, T. Trent, S. Trippe, S. Tsuda, I. V. Bemmel, H. J. van Langevelde, D. R. van Rossum, J. Wagner, J. Wardle, J. Weintroub, N. Wex, R. Wharton, M. Wielgus, G. N. Wong, Q. Wu, K. Young, A. Young, F. Yuan, Y.-F. Yuan, J. A. Zensus, G. Zhao, S.-S. Zhao, Z. Zhu, and The Event Horizon Telescope Collaboration. 2019. The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project The Astrophysical Journal Supplement Series 243 (2): 26 [10.3847/1538-4365/ab29fd]

Schnittman, J. D., T. Dal Canton, J. Camp, D. Tsang, and B. J. Kelly. 2018. Electromagnetic Chirps from Neutron Star-Black Hole Mergers The Astrophysical Journal 853 123 [10.3847/1538-4357/aaa08b]

Kelly, B. J., J. G. Baker, Z. B. Etienne, B. Giacomazzo, and J. D. Schnittman. 2017. Prompt electromagnetic transients from binary black hole mergers Physical Review D 96 123003 [10.1103/PhysRevD.96.123003]

Kelly, B. J., J. G. Baker, Z. B. Etienne, B. Giacomazzo, and J. Schnittman. 2017. Prompt Electromagnetic Transients from Binary Black Hole Mergers Physical Review D 96 123003

Etienne, Z. B., J. G. Baker, V. Paschalidis, B. J. Kelly, and S. L. Shapiro. 2014. Improved moving puncture gauge conditions for compact binary evolutions Physical Review D 90 064032 [10.1103/PhysRevD.90.064032]

Littenberg, T. B., J. G. Baker, A. Buonanno, and B. J. Kelly. 2013. Systematic biases in parameter estimation of binary black-hole mergers Physical Review D 87 104003 [10.1103/PhysRevD.87.104003]

Kelly, B. J., and J. G. Baker. 2013. Decoding mode mixing in black-hole merger ringdown Physical Review D 87 084004 [10.1103/PhysRevD.87.084004]

Kelly, B. J., J. G. Baker, W. D. Boggs, S. T. McWilliams, and J. M. Centrella. 2011. Mergers of black-hole binaries with aligned spins: Waveform characteristics Physical Review D 84 084009 [10.1103/PhysRevD.84.084009]

Mundim, B. C., B. J. Kelly, H. Nakano, Y. Zlochower, and M. Campanelli. 2011. Hybrid black-hole binary initial data Classical and Quantum Gravity 28 134003 [doi:10.1088/0264-9381/28/13/134003]

Centrella, J. M., J. G. Baker, B. J. Kelly, and J. R. Van Meter. 2011. Merging Black Holes Contemporary Physics 52 1 [10.1080/00107514.2010.520908]

Centrella, J. M., J. G. Baker, B. J. Kelly, and J. R. Van Meter. 2010. The final merger of black-hole binaries Annual Reviews of Nuclear and Particle Science 60 75 [10.1146/annurev.nucl.010909.083246]

Kelly, B. J., W. Tichy, Y. Zlochower, M. Campanelli, and B. F. Whiting. 2010. Post-Newtonian Initial Data with Waves: Progress in Evolution Classical and Quantum Gravity 27 114005 [doi:10.1088/0264-9381/27/11/114005]

McWilliams, S. T., (. I. Thorpe, J. G. Baker, and B. J. Kelly. 2010. Impact of mergers on LISA parameter estimation for nonspinning black hole binaries Physical Review D 81 064014 [10.1103/PhysRevD.81.064014]

Centrella, J. M., J. G. Baker, B. J. Kelly, and J. R. Van Meter. 2010. Black-hole binaries, gravitational waves, and numerical relativity Reviews of Modern Physics 82 3069-3119 [10.1103/RevModPhys.82.3069]

van Meter, J. R., M. C. Miller, J. G. Baker, W. D. Boggs, and B. J. Kelly. 2010. Test of a General Formula for Black Hole Gravitational Wave Kicks The Astrophysical Journal 719 1427 [10.1088/0004-637X/719/2/1427]

McWilliams, S. T., B. J. Kelly, and J. G. Baker. 2010. Observing mergers of nonspinning black-hole binaries Physical Review D 82 024014 [10.1103/PhysRevD.82.024014]

van Meter, J. R., J. H. Wise, M. C. Miller, et al. C. S. Reynolds, J. Centrella, J. G. Baker, W. D. Boggs, B. J. Kelly, and S. T. McWilliams. 2010. Modeling Flows around Merging Black Hole Binaries The Astrophysical Journal Letters 711 L89 [10.1088/2041-8205/711/2/L89]

Hannam, M., S. Husa, J. G. Baker, et al. M. Boyle, B. Brügmann, T. Chu, N. Dorband, F. Herrmann, I. Hinder, B. J. Kelly, L. E. Kidder, P. Laguna, K. D. Matthews, J. R. Van Meter, H. P. Pfeiffer, D. Pollney, C. Reisswig, M. A. Scheel, and D. Shoemaker. 2009. Samurai project: Verifying the consistency of black-hole-binary waveforms for gravitational-wave detection Physical Review D 79 084025 [10.1103/PhysRevD.79.084025]

Thorpe, J. I., S. T. McWilliams, B. J. Kelly, et al. R. P. Fahey, K. A. Arnaud, and J. G. Baker. 2009. LISA parameter estimation using numerical merger waveforms Classical and Quantum Gravity 26 094026 [10.1088/0264-9381/26/9/094026]

Cadonati, L., B. Aylott, J. G. Baker, et al. W. D. Boggs, M. Boyle, P. R. Brady, D. A. Brown, B. Brügmann, L. T. Buchman, A. Buonanno, J. Camp, M. Campanelli, J. Centrella, S. Chatterji, N. Christensen, T. Chu, P. Diener, N. Dorband, Z. B. Etienne, J. Faber, S. Fairhurst, B. Farr, S. Fischetti, G. Guidi, L. M. Goggin, M. Hannam, F. Herrmann, I. Hinder, S. Husa, V. Kalogera, D. Keppel, L. E. Kidder, B. J. Kelly, B. Krishnan, P. Laguna, C. O. Lousto, I. Mandel, P. Marronetti, R. Matzner, S. T. McWilliams, K. D. Matthews, R. A. Mercer, S. R. Mohapatra, A. H. Mroué, H. Nakano, E. Ochsner, Y. Pan, L. Pekowsky, H. P. Pfeiffer, D. Pollney, F. Pretorius, V. Raymond, C. Reisswig, L. Rezzolla, O. Rinne, C. Robinson, C. Röver, L. Santamaría, B. Sathyaprakash, M. A. Scheel, E. Schnetter, J. Seiler, S. L. Shapiro, D. Shoemaker, U. Sperhake, A. Stroeer, R. Sturani, W. Tichy, Y. T. Liu, M. van der Sluys, J. R. van Meter, R. Vaulin, A. Vecchio, J. Veitch, A. Viceré, J. T. Whelan, and Y. Zlochower. 2009. Status of NINJA: the Numerical INJection Analysis project Classical and Quantum Gravity 26 4008 [10.1088/0264-9381/26/11/114008]

Aylott, B., J. G. Baker, W. D. Boggs, et al. M. Boyle, P. R. Brady, D. A. Brown, B. Brügmann, L. T. Buchman, A. Buonanno, L. Cadonati, J. Camp, M. Campanelli, J. Centrella, S. Chatterji, N. Christensen, T. Chu, P. Diener, N. Dorband, Z. B. Etienne, J. Faber, S. Fairhurst, B. Farr, S. Fischetti, G. Guidi, L. M. Goggin, M. Hannam, F. Herrmann, I. Hinder, S. Husa, V. Kalogera, D. Keppel, L. E. Kidder, B. J. Kelly, B. Krishnan, P. Laguna, C. O. Lousto, I. Mandel, P. Marronetti, R. Matzner, S. T. McWilliams, K. D. Matthews, R. A. Mercer, S. R. Mohapatra, A. H. Mroué, H. Nakano, E. Ochsner, Y. Pan, L. Pekowsky, H. A. Pfeiffer, D. Pollney, F. Pretorius, V. Raymond, C. Reisswig, L. Rezzolla, O. Rinne, C. Robinson, C. Röver, L. Santamaría, B. Sathyaprakash, M. A. Scheel, E. Schnetter, J. Seiler, S. L. Shapiro, D. Shoemaker, U. Sperhake, A. Stroeer, R. Sturani, W. Tichy, Y. T. Liu, M. van der Sluys, J. R. van Meter, R. Vaulin, A. Vecchio, J. Veitch, A. Viceré, J. T. Whelan, and Y. Zlochower. 2009. Testing gravitational-wave searches with numerical relativity waveforms: results from the first Numerical INJection Analysis (NINJA) project Classical and Quantum Gravity 26 5008 [10.1088/0264-9381/26/16/165008]

Schnittman, J. D., A. Buonanno, J. R. Van Meter, et al. J. G. Baker, W. D. Boggs, J. M. Centrella, B. J. Kelly, and S. T. McWilliams. 2008. Anatomy of the binary black hole recoil: A multipolar analysis Physical Review D 77 044031 [10.1103/PhysRevD.77.044031]

Pan, Y., A. Buonanno, J. G. Baker, et al. J. M. Centrella, B. J. Kelly, S. T. McWilliams, F. Pretorius, and J. R. Van Meter. 2008. Data-analysis driven comparison of analytic and numerical coalescing binary waveforms: Nonspinning case Physical Review D 77 024014 [10.1103/PhysRevD.77.024014]

Baker, J. G., W. D. Boggs, J. M. Centrella, et al. B. J. Kelly, S. T. McWilliams, and J. R. Van Meter. 2008. Mergers of nonspinning black-hole binaries: Gravitational radiation characteristics Physical Review D 78 044046 [10.1103/PhysRevD.78.044046]

Baker, J. G., W. D. Boggs, J. Centrella, et al. B. J. Kelly, S. T. McWilliams, M. C. Miller, and J. R. van Meter. 2008. Modeling Kicks from the Merger of Generic Black Hole Binaries The Astrophysical Journal 682 L29 [10.1086/590927]

Buonanno, A., Y. Pan, J. G. Baker, et al. J. M. Centrella, B. J. Kelly, S. T. McWilliams, and J. R. Van Meter. 2007. Approaching faithful templates for non-spinning binary black holes using the effective-one-body approach Physical Review D 76 104049 [10.1103/PhysRevD.76.104049]

Baker, J. G., J. R. Van Meter, S. T. McWilliams, J. M. Centrella, and B. J. Kelly. 2007. Consistency of post-Newtonian waveforms with numerical relativity Physical Review Letters 99 181101 [10.1103/PhysRevLett.99.181101]

Kelly, B. J., W. Tichy, M. Campanelli, and B. F. Whiting. 2007. Black hole puncture initial data with realistic gravitational wave content Physical Review D 76 024008 [10.1103/PhysRevD.76.024008]

Choi, D.-I., B. J. Kelly, W. D. Boggs, et al. J. G. Baker, J. M. Centrella, and J. R. Van Meter. 2007. Recoiling from a kick in the head-on collision of spinning black holes Physical Review D 76 104026 [10.1103/PhysRevD.76.104026]

Baker, J. G., S. T. McWilliams, J. R. Van Meter, et al. J. M. Centrella, D.-I. Choi, B. J. Kelly, and M. Koppitz. 2007. Binary black hole late inspiral: Simulations for gravitational wave observations Physical Review D 75 124024 [10.1103/PhysRevD.75.124024]

Baker, J. G., W. D. Boggs, J. Centrella, et al. B. J. Kelly, S. T. McWilliams, M. C. Miller, and J. R. Van Meter. 2007. Modeling Kicks from the Merger of Nonprecessing Black Hole Binaries The Astrophysical Journal 668 1140 [10.1086/521330]

Campanelli, M., B. J. Kelly, and C. O. Lousto. 2006. The Lazarus Project. II. Spacelike extraction with the quasi-Kinnersley tetrad Physical Review D 73 064005 [10.1103/PhysRevD.73.064005]

Sperhake, U., B. J. Kelly, P. Laguna, K. L. Smith, and E. Schnetter. 2005. Black hole head-on collisions and gravitational waves with fixed mesh-refinement and dynamic singularity excision Physical Review D 71 124042 [10.1103/PhysRevD.71.124042]

Sperhake, U., K. L. Smith, B. J. Kelly, P. Laguna, and D. M. Shoemaker. 2004. Impact of densitized lapse slicings on evolutions of a wobbling black hole Physical Review D 69 024012 [10.1103/PhysRevD.69.024012]

Dreyer, O., B. J. Kelly, B. Krishnan, et al. L. S. Finn, D. Garrison, and R. Lopez-Aleman. 2004. Black-hole spectroscopy: testing general relativity through gravitational-wave observations Classical and Quantum Gravity 21 787 [10.1088/0264-9381/21/4/003]

Kelly, B. J., P. Laguna, K. Lockitch, et al. J. Pullin, E. Schnetter, D. M. Shoemaker, and M. Tiglio. 2001. Cure for unstable numerical evolutions of single black holes: Adjusting the standard ADM equations in the spherically symmetric case Physical Review D 64 084013 [10.1103/PhysRevD.64.084013]

Selected Public Outreach


Ask an Astrophysicist

December 2011 - Present

Volunteer for one-week shifts as part of two-person team answering questions on astronomy & astrophysics, collected through the Ask an Astrophysicist web page.


NASA Science Live: Black Holes 101

December 2019 - December 2019

Participated in an episode of NASA's Science Live program, discussing what black holes are, and how we deterct them.

Professional Societies


American Physical Society

1999 - Present


International Society on General Relativity and Gravitation

2007 - Present


Institute of Physics (U.K.)

2008 - Present


American Astronomical Society

2013 - Present