A very fast and angular momentum conserving tree code
DC Marcello - The Astronomical Journal, 2017 - iopscience.iop.org
The Astronomical Journal, 2017•iopscience.iop.org
There are many methods used to compute the classical gravitational field in astrophysical
simulation codes. With the exception of the typically impractical method of direct
computation, none ensure conservation of angular momentum to machine precision. Under
uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the
very fast tree code) conserves linear momentum to machine precision. We show that it is
possible to modify this method in a way that conserves both angular and linear momenta.
simulation codes. With the exception of the typically impractical method of direct
computation, none ensure conservation of angular momentum to machine precision. Under
uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the
very fast tree code) conserves linear momentum to machine precision. We show that it is
possible to modify this method in a way that conserves both angular and linear momenta.
Abstract
There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.
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