343 citations · 1k across the 20 of their papers we have counts for
18 papers · 1 filter
Time-reversible timestepping in many-body planetary systems
David M. Hernandez, Tenri Jinno, Junichiro Makino
Simulating chaotic planetary system evolution requires resolving small time-scales due to close encounters, scattering, collisions, and more. Simulations typically assign fixed tim…
Mercury's chaotic secular evolution as a subdiffusive process
Dorian S. Abbot, Robert J. Webber, David M. Hernandez +2
Mercury's orbit can destabilize, generally resulting in a collision with either Venus or the Sun. Chaotic evolution can cause g1 to decrease to the approximately constant value of…
ASSIST: An Ephemeris-Quality Test Particle Integrator
Matthew J. Holman, Arya Akmal, Davide Farnocchia +5
We introduce ASSIST, a software package for ephemeris-quality integrations of test particles. ASSIST is an extension of the REBOUND framework and makes use of its IAS15 integrator…
Switching integrators reversibly in the astrophysical -body problem
David M. Hernandez, Walter Dehnen
We present a simple algorithm to switch between -body time integrators in a reversible way. We apply it to planetary systems undergoing arbitrarily close encounters and highly e…
Simple physics and integrators accurately reproduce Mercury instability statistics
Dorian S. Abbot, David M. Hernandez, Sam Hadden +3
The long-term stability of the Solar System is an issue of significant scientific and philosophical interest. The mechanism leading to instability is Mercury's eccentricity being p…
Stepsize errors in the -body problem: discerning Mercury's true possible long-term orbits
David M. Hernandez, Richard E. Zeebe, Sam Hadden
Numerical integrations of the Solar System have been carried out for decades. Their results have been used, for example, to determine whether the Solar System is chaotic, whether M…
A differentiable N-body code for transit timing and dynamical modeling. I. Algorithm and derivatives
Eric Agol, David M. Hernandez, Zachary Langford
When fitting N-body models to astronomical data - including transit times, radial velocity, and astrometric positions at observed times - the derivatives of the model outputs with…
Significant improvement in planetary system simulations from statistical averaging
David M. Hernandez, Eric Agol, Matthew J. Holman +1
Symplectic integrators are widely used for the study of planetary dynamics and other -body problems. In a study of the outer Solar system, we demonstrate that individual symplec…
EnckeHH: an integrator for gravitational dynamics with a dominant mass that achieves optimal error behaviour
David M. Hernandez, Matthew J. Holman
We present EnckeHH, a new, highly accurate code for orbital dynamics of perturbed Keplerian systems such as planetary systems or galactic centre systems. It solves Encke's equation…
Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides
Eric Agol, Caroline Dorn, Simon L. Grimm +32
We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST and K2 transit time measurements, and…
Are long-term -body simulations reliable?
David M. Hernandez, Sam Hadden, Junichiro Makino
-body integrations are used to model a wide range of astrophysical dynamics, but they suffer from errors which make their orbits diverge exponentially in time from the correct o…
REBOUNDx: A Library for Adding Conservative and Dissipative Forces to Otherwise Symplectic N-body Integrations
Daniel Tamayo, Hanno Rein, Pengshuai Shi +1
Symplectic methods, in particular the Wisdom-Holman map, have revolutionized our ability to model the long-term, conservative dynamics of planetary systems. However, many astrophys…
Improving the accuracy of simulated chaotic -body orbits using smoothness
David M. Hernandez
Symplectic integrators are a foundation to the study of dynamical -body phenomena, at scales ranging from from planetary to cosmological. These integrators preserve the Poincaré…
Should -body integrators be symplectic everywhere in phase space?
David M. Hernandez
Symplectic integrators are the preferred method of solving conservative -body problems in cosmological, stellar cluster, and planetary system simulations because of their superi…
Hybrid Symplectic Integrators for Planetary Dynamics
Hanno Rein, David M. Hernandez, Daniel Tamayo +6
Hybrid symplectic integrators such as MERCURY are widely used to simulate complex dynamical phenomena in planetary dynamics that could otherwise not be investigated. A hybrid integ…
The nature of the TRAPPIST-1 exoplanets
Simon L. Grimm, Brice-Olivier Demory, Michaël Gillon +23
Context. The TRAPPIST-1 system hosts seven Earth-sized, temperate exoplanets orbiting an ultra-cool dwarf star. As such, it represents a remarkable setting to study the formation a…
A study of symplectic integrators for planetary system problems: error analysis and comparisons
David M. Hernandez, Walter Dehnen
The symplectic Wisdom-Holman map revolutionized long-term integrations of planetary systems. There is freedom in such methods of how to split the Hamiltonian and which coordinate s…
Fast and reliable symplectic integration for planetary system -body problems
David M. Hernandez
We apply one of the exactly symplectic integrators, that we call HB15, of \cite{HB15}, along with the Kepler problem solver of \cite{WH15}, to solve planetary system -body probl…