David M. Hernandez

Biographical Sketch

David M. Hernandez (not to be confused with this David Hernandez) is a CycloAstro fellow at Yale University. Previously, he was a Minor Planet Center Fellow and Institute for Theory and Computation associate at the Harvard--Smithsonian Center for Astrophysics (CfA). David obtained his Bachelor of Science degree at the University of Arizona, where he was an Arizona Flinn Scholar and U.S. Goldwater Scholar. David completed his PhD in June 2018 at MIT, where he was an NSF Graduate Research Fellow, and held a three-year MIT Lyons fellowship and a Shah Zion fellowship. His thesis, "Solving the N-body problem in astrophysics'', was supervised by Ed Bertschinger. David's thesis committee also included Mark Vogelsberger and Jesse Thaler. David also held brief postdoctoral positions at RIKEN CCS and MIT.

A shortened CV is available here.

Research

David is a theoretical and computational astrophysicist. David's research focuses on applications of the mathematical N-body problem, which describes the motions of planets, stars, and galaxies. Please check the publications section for more.

• Eric Agol, Edmund Bertschinger, Romeel Dave, Walter Dehnen, Sam Hadden, Matthew J. Holman, Junichiro Makino, Margaret Pan, Hanno Rein, Daniel Tamayo, Frank van den Bosch, Long Wang, Jack Wisdom, Richard Zeebe.

Codes

Links to some open-source codes I have worked on are available below. For other codes, feel free to contact me.

• celmech
• EnckeHH
• MERCURIUS (part of Rebound)
• NbodyGradient
• ReboundX
• Universal.c. This version has been updated from the version in Wisdom and Hernandez (2015), as described in Hernandez and Holman (2020).

Publications

A Google Scholar profile available here. A NASA ADS listing is available here.

1. ''Switching integrators reversibly in the astrophysical N-body problem'' David M. Hernandez and Walter Dehnen 2023, submitted to MNRAS
2. ''Simple physics and integrators accurately reproduce Mercury instability statistics'' Dorian S. Abbot, David M. Hernandez, Sam Hadden, Robert J. Webber, Georgios P. Afentakis, Jonathan Weare 2022, submitted to ApJ
3. ''Stepsize errors in the N-body problem: discerning Mercury’s true possible long-term orbits'' David M. Hernandez, Richard E. Zeebe, Sam Hadden 2022, MNRAS 510, 4302.
4. ''On the reliability of simulations of collisional stellar systems'' Long Wang and David M. Hernandez 2022, submitted to MNRAS.
5. ''A differentiable N-body code for transit timing and dynamical modeling. I. Algorithm and derivatives'' Eric Agol, David M. Hernandez, Zachary Langford 2021, MNRAS 507, 1582.
6. ''Significant Improvement in Planetary System Simulations from Statistical Averaging'' David M. Hernandez, Eric Agol, Matthew J. Holman, and Sam Hadden 2021, RNAAS 5, 77.
7. ''ENCKEHH: an integrator for gravitational dynamics with a dominant mass that achieves optimal error behaviour'' David M. Hernandez and Matthew J. Holman 2021, MNRAS 502, 556.
8. ''Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides'' Eric Agol and 34 coauthors including David M. Hernandez 2020, PSJ 2, 1.
9. ''Are long-term N-body simulations reliable?'' David M. Hernandez, Sam Hadden, and Junichiro Makino 2020, MNRAS 493, 1913.
10. ''REBOUNDx: a library for adding conservative and dissipative forces to otherwise symplectic N-body integrations'' Daniel Tamayo, Hanno Rein, Pengshuai Shi, and David M. Hernandez 2020, MNRAS 491, 2885.
11. ''Improving the accuracy of simulated chaotic N-body orbits using smoothness'' David M. Hernandez 2019, MNRAS 490, 4175.
12. ''Should N-body integrators be symplectic everywhere in phase space?'' David M. Hernandez 2019, MNRAS 486, 5231.
13. ''Hybrid symplectic integrators for planetary dynamics'' Hanno Rein, David M. Hernandez, Daniel Tamayo, and 6 coauthors 2019, MNRAS 485, 5490.
14. ''The nature of the TRAPPIST--1 exoplanets'' Simon L. Grimm and 26 coauthors including David M. Hernandez 2018, A&A 613, A68.
15. ''Time-symmetric integration in astrophysics'' David M. Hernandez and Edmund Bertschinger 2018, MNRAS 475, 5570.
16. ''A study of symplectic integrators for planetary system problems: error analysis and comparisons'' David M. Hernandez and Walter Dehnen 2017, MNRAS 468, 2614.
17. ''Symplectic fourth-order maps for the collisional N-body problem'' Walter Dehnen and David M. Hernandez 2017, MNRAS 465, 1201.
18. ''Fast and reliable symplectic integration for planetary system N-body problems'' David M. Hernandez 2016, MNRAS 458, 4285.
19. ''A Fast and Accurate Universal Kepler Solver without Stumpff Series'' Jack Wisdom and David M. Hernandez 2015, MNRAS 453, 3015.
20. ''Symplectic integration for the collisional gravitational N-body problem'' David M. Hernandez and Edmund Bertschinger 2015, MNRAS 452, 1934.