Knowra N-body simulation N-body simulation An N-body simulation numerically predicts the motion of many mutually gravitating bodies by repeatedly calculating their forces and updating their positions and velocities.
Newton's law of universal gravitation : A physical law stating that every pair of masses attracts with a force proportional to their masses and inversely proportional to their separation squared. It supplies the pairwise gravitational forces that the simulation sums.
Cosmological N-body simulation : A simulation of cosmic matter evolving under gravity, commonly used to model the formation of large-scale structure. It follows dark matter and galaxies across expanding volumes of the universe.
Direct summation : A method that calculates every pairwise interaction explicitly. It is the accurate baseline for gravitational forces but scales quadratically with body count.
Initial conditions : The starting positions, velocities, masses, and other state variables supplied to a dynamical calculation. A simulation's predicted evolution depends on its chosen initial state.
Numerical integration : The approximation of a continuous mathematical process by computations over discrete steps. A simulation advances positions and velocities through time using finite steps.
Galaxy formation : The physical processes through which gas, stars, and dark matter assemble into galaxies. Gravitational simulations model how dark matter halos grow and merge around galaxies.
Particle-mesh method : A force-computation method that maps particles onto a grid, solves fields on that grid, and interpolates forces back. It replaces many pairwise calculations with a grid-based approximation for long-range gravity.
Hamiltonian mechanics : A formulation of classical mechanics based on a system's coordinates, momenta, and energy function. It explains why gravitational trajectories and energy conservation guide integrator design.
Leapfrog integration : A time-stepping method that alternates updates of positions and velocities, often preserving energy behavior well in orbital systems. Its long-term stability makes it a common choice for gravitational trajectories.
Star cluster : A gravitationally bound group of stars that formed from the same molecular cloud or became bound later. Simulations track stellar encounters, relaxation, and eventual cluster evolution.
Show all 22