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N-body simulation

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1076:-body simulations give findings on the large-scale dark matter distribution and the structure of dark matter halos. According to simulations of cold dark matter, the overall distribution of dark matter on a large scale is not entirely uniform. Instead, it displays a structure resembling a network, consisting of voids, walls, filaments, and halos. Also, simulations show that the relationship between the concentration of halos and factors such as mass, initial fluctuation spectrum, and cosmological parameters is linked to the actual formation time of the halos. In particular, halos with lower mass tend to form earlier, and as a result, have higher concentrations due to the higher density of the Universe at the time of their formation. Shapes of halos are found to deviate from being perfectly spherical. Typically, halos are found to be elongated and become increasingly prolate towards their centers. However, interactions between dark matter and 4434: 51: 1211:, and some fundamental object containing this data, as well as the mass of an orbiting body. This method is applicable to other types of N-body simulations as well; a simulation of point masses with charges would use a similar method, however the force would be due to attraction or repulsion by interaction of electric fields. Regardless, acceleration of particle is a result of summed force vectors, divided by the mass of the particle: 450:-body codes for astrophysical applications which use adaptive (hierarchical) time steps, an Ahmad-Cohen neighbour scheme and regularization of close encounters. Regularization is a mathematical trick to remove the singularity in the Newtonian law of gravitation for two particles which approach each other arbitrarily close. Sverre Aarseth's codes are used to study the dynamics of star clusters, planetary systems and galactic nuclei. 349: 332:, after determining the initial conditions of dark matter particles. The conventional method employed for initializing positions and velocities of dark matter particles involves moving particles within a uniform Cartesian lattice or a glass-like particle configuration. This is done by using a linear theory approximation or a low-order 880:
and computing the inverse Fourier transform (or computing the inverse transform and then using some other method). Since this method is limited by the mesh size, in practice a smaller mesh or some other technique (such as combining with a tree or simple particle-particle algorithm) is used to compute
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Newtonian force law is used, which does not diverge as the inverse-square radius at short distances. Most simulations implement this quite naturally by running the simulations on cells of finite size. It is important to implement the discretization procedure in such a way that particles always exert
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in 1941, determining the forces between stars in encountering galaxies via the mathematical equivalence between light propagation and gravitational interaction: putting light bulbs at the positions of the stars and measuring the directional light fluxes at the positions of the stars by a photo cell,
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can otherwise be ignored, as typical dynamical timescales are long compared to the light crossing time for the simulation, and the space-time curvature induced by the particles and the particle velocities are small. The boundary conditions of these cosmological simulations are usually periodic (or
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particles under the influence of their mutual gravitational forces are integrated numerically without any simplifying approximations. These calculations are used in situations where interactions between individual objects, such as stars or planets, are important to the evolution of the system.
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expansion). This can dramatically reduce the number of particle pair interactions that must be computed. To prevent the simulation from becoming swamped by computing particle-particle interactions, the cells must be refined to smaller cells in denser parts of the simulation which contain many
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is usually used to divide the volume into cubic cells and only interactions between particles from nearby cells need to be treated individually; particles in distant cells can be treated collectively as a single large particle centered at the distant cell's center of mass (or as a low-order
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The 'particles' treated by the simulation may or may not correspond to physical objects which are particulate in nature. For example, an N-body simulation of a star cluster might have a particle per star, so each particle has some physical significance. On the other hand, a simulation of a
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of the simulation, merely initial positions are needed, but this will not allow propagation- initial velocities are required. Consider a planet orbiting a star- it has no motion, but is subject to gravitational attraction to its host star. As a time progresses, and time
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into the simulations dramatically increases their complexity and often radical simplifications of the underlying physics must be made. However, this is an extremely important area and many modern simulations are now trying to understand processes that occur during
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The path of a small planet, comet, or long-range spacecraft can often be accurately modeled starting from the 2-body elliptical orbit around the Sun, and adding small corrections from the gravitational attraction of the larger planets in their known orbits.
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is a variable which will remain at 0 temporarily, but allows for future inclusion of significant numbers of asteroids, at the users discretion. A critical step for the configuration of simulations is to establish the time ranges of the simulation,
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An entire simulation can consist of hundreds, thousands, millions, billions, or sometimes trillions of time steps. At the elementary level, each time step (for simulations with particles moving due to forces exerted on them) involves
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One of the simplest refinements is that each particle carries with it its own timestep variable, so that particles with widely different dynamical times don't all have to be evolved forward at the rate of that with the shortest time.
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Some characteristics of the long-term paths of a system of particles can be calculated directly. The actual path of any particular particle does not need to be calculated as an intermediate step. Such characteristics include
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method for containing kinematic data for a particle is the use of fixed length arrays, which in optimised code allows for easy memory allocation and prediction of consumed resources; as seen in the following C++ code:
762: 1033: 1268: 904:. The path of a satellite closely orbiting the Earth can be accurately modeled starting from the 2-body elliptical orbit around the center of the Earth, and adding small corrections due to the 843: 651: 524:. However all numerical integration leads to errors. Smaller steps give lower errors but run more slowly. Leapfrog integration is roughly 2nd order on the timestep, other integrators such as 3286: 2469:
A solar-system-like simulation can be accomplished by taking average distances of planet equivalent point masses from a central star. To keep code simple, a non-rigorous approach based on
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is a naive propagation of orbiting bodies; naive implying that the only forces acting on the orbiting bodies is the gravitational force which they exert on each other. In
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plays an important role in the formation of galaxies. The time evolution of the density f (in phase space) of dark matter particles, can be described by the collisionless
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Although there are millions or billions of particles in typical simulations, they typically correspond to a real particle with a very large mass, typically 10
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systems. As the particles are meant to represent large numbers of dark matter particles or groups of stars, these binaries are unphysical. To prevent this, a
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would affect the internal structure of dark matter halos. Simulations that model both dark matters and baryons are needed to study small-scale structures.
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bodies satisfying a fixed electrostatic potential law, determining if a body reaches a destination ball in a given time bound where we require a poly(
977: 173:). This quantity needs not have any physical significance, but must be chosen as a compromise between accuracy and manageable computer requirements. 3436: 3339: 4966: 1216: 881:
the small-scale forces. Sometimes an adaptive mesh is used, in which the mesh cells are much smaller in the denser regions of the simulation.
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is static, however, from the perspective of an observer seeing only position, it will take two time steps to see a change in velocity.
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Navarro, Julio F.; Frenk, Carlos S.; White, Simon D. M. (December 1997). "A Universal Density Profile from Hierarchical Clustering".
597:, particles are assumed to be divided between the surrounding 2x2 vertices of the mesh. The potential energy Φ can be found with the 4554:"A comparison of the evolution of density fields in perturbation theory and numerical simulations - II. Counts-in-cells analysis" 2210:, the resultant acceleration of a body due to its neighbouring masses is independent of its velocity, however, for the time step 1203:
is useful for establishing the fundamental mathematical structures as well as data containers required for propagation; namely
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reaches the destination ball, the problem is PSPACE-hard. These bounds are based on similar complexity bounds obtained for
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Callahan, Paul B.; Kosaraju, Sambasiva Rao (1992). "A decomposition of multidimensional point sets with applications to
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There are two basic approximation schemes to decrease the computational time for such simulations. These can reduce the
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included ten billion) and the number of particle-particle interactions needing to be computed increases on the order of
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cannot afford to have a particle for each atom or molecule of gas as this would require on the order of
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is the softening parameter. The value of the softening parameter should be set small enough to keep
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for these bodies must be reserved before the bodies are configured; to allow for scalability, a
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are added, it will gather velocity according to its acceleration. For a given instant in time,
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are significant. This is incorporated in the simulation as an evolving measure of distance (or
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of particles involved is usually very large (typical simulations include many millions, the
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of their physical energy). However, the contributions of general relativity and the finite
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system, which causes the particles to slow in comoving coordinates (as well as due to the
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in the simulation, the trajectories resulting from the above propagation is shown below:
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toroidal), so that one edge of the simulation volume matches up with the opposite edge.
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Numerical integration is usually performed over small timesteps using a method such as
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particles per cell. For simulations where particles are not evenly distributed, the
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Bertschinger, Edmund (1998). "Simulations of structure formation in the universe".
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algorithms are used to get fairly accurate estimates of the path of objects in the
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The positions and velocities established above are interpreted to be correct for
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in which space is discretised on a mesh and, for the purposes of computing the
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John H. Reif; Stephen R. Tate (1993). "The Complexity of N-body Simulation".
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This article is about a topic in physics. For the automobile platform, see
2115:, the projection of the objects velocity vector in Cartesian space along 2034:, the projection of the objects velocity vector in Cartesian space along 1953:, the projection of the objects velocity vector in Cartesian space along 1872:, the projection of the objects position vector in Cartesian space along 1800:, the projection of the objects position vector in Cartesian space along 1728:, the projection of the objects position vector in Cartesian space along 4974: 4721: 4566: 1273: 795:
is the comoving wavenumber and the hats denote Fourier transforms. Since
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For engineering problems and simulations involving many components, see
4935:-nearest-neighbors and n-body potential fields (preliminary version)". 3532: 1058: 961: 937: 435: 81:
of particles, usually under the influence of physical forces, such as
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effort. The first purely calculational simulations were then done by
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is a numerical trick used in N-body techniques to prevent numerical
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The extent of a simulation would logically be for the period where
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Commonly, N-body simulations will be systems based on some type of
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N-body simulation of 400 objects with parameters close to those of
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goes to infinity). This is obtained by modifying the regularized
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is the velocity, and Φ is the gravitational potential given by
144:-body simulations are used to study the dynamical evolution of 100:, from investigating the dynamics of few-body systems like the 4456: â€“ All of space observable from the Earth at the present 1196: 965: 845:, the gravitational field can now be found by multiplying by 683:
is the density (number of particles at the mesh points). The
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Incorporating baryons, leptons and photons into simulations
372:-body simulations, the equations of motion of a system of 105: 2165: 339: 1125:-body reachability problem is defined as follows – given 109: 1263:{\displaystyle {\vec {a}}={\frac {1}{m}}\sum {\vec {F}}} 1165:
The simplest implementation of N-body simulations where
4772:. Lecture Notes in Computer Science. pp. 162–176. 4458:
Pages displaying short descriptions of redirect targets
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On the other hand, if the question is whether the body
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Many simulations are large enough that the effects of
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Numerical methods for ordinary differential equations
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when a particle comes too close to another (and the
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Theory of Computing 3281:{\displaystyle t_{0}\leq t<t_{\text{end}}} 2303:, as the shift in position is calculated via 884: 464:Friedmann-Lemaitre-Robertson-Walker cosmology 112:system to understanding the evolution of the 27:Simulation of a dynamical system of particles 4878: 3304:calculating the accelerations of each body ( 3106:which will progress the simulation forward: 1272:An example of a programmatically stable and 900:People often decide to put a satellite in a 528:can have 4th order accuracy or much higher. 486: 4881:Annual Review of Astronomy and Astrophysics 4820: 4796: 4659: 4493: â€“ Computer simulation of the universe 4450: â€“ Computer simulation of the universe 3433:calculating the new position of each body ( 1116: 687:can solve this efficiently by going to the 581:) time per iteration with fixed dimension. 96:-body simulations are widely used tools in 4967: 4953: 4592: 2134: 2130: 2053: 2049: 1972: 1968: 1891: 1887: 1819: 1815: 1747: 1743: 1160: 151: 4777: 4720: 4691: 4634: 4616: 4575: 4565: 4536: 4510: 3336:calculating the velocities of each body ( 642: 176: 165:particles for each mole of material (see 4828:-Körper-Problemes fĂĽr Sternhaufen. II". 4824:(1963). "Die numerische Integration des 4665: 347: 49: 4908:Binney, James; Tremaine, Scott (1987). 4858:-body Simulations: Tools and Algorithms 4848: 4598: 3083:, as well as the incremental time step 2166:Initialisation of simulation parameters 2162:contains enough room for a mass value. 931: 584: 14: 5142: 1155: 384:-body simulations were carried out by 4948: 4504: 2276:is only dependent on its velocity at 114:large-scale structure of the universe 4513:"N-body simulations (gravitational)" 3555:exists in the aforementioned range: 3183:// approximately a decade in seconds 4770:Automata, Languages and Programming 4511:Trenti, Michele; Hut, Piet (2008). 4454:Large-scale structure of the cosmos 3301:calculating the forces on each body 24: 4790: 4417: 3512: 3415: 2473:and mean velocities will is used. 2405: 981: 832: 823: 703: 619: 610: 287: 284: 270: 262: 250: 230: 222: 25: 5186: 4599:Jenkins, Adrian (21 April 2010). 949:a vanishing force on themselves. 567:well-separated pair decomposition 501:defining the particle motions in 5103:Backward differentiation formula 4636:10.1111/j.1365-2966.2010.16259.x 4432: 1121:Reif and Tate prove that if the 310: 274: 243: 4491:Bolshoi cosmological simulation 2459:{\textstyle {\vec {v}}_{t_{n}}} 1088:Many simulations simulate only 542: 499:ordinary differential equations 380:The first direct gravitational 171:Smoothed Particle Hydrodynamics 4901:10.1146/annurev.astro.36.1.599 4761: 4469:Galaxy formation and evolution 3497: 3475: 3447: 3400: 3372: 3350: 3317: 3291: 3076:{\displaystyle t_{\text{end}}} 3017:// a planet similar to neptune 2855:// a planet similar to jupiter 2639:// a planet similar to mercury 2437: 2383: 2354: 2319: 1254: 1226: 864: 826: 808: 779: 734: 706: 454:General relativity simulations 432:Astronomisches Rechen-Institut 411: 405: 13: 1: 4497: 2963:// a planet similar to uranus 2909:// a planet similar to saturn 2108:{\textstyle e_{5}={\dot {z}}} 2027:{\textstyle e_{4}={\dot {y}}} 1946:{\textstyle e_{3}={\dot {x}}} 2747:// a planet similar to earth 2693:// a planet similar to venus 2585:// a star similar to the sun 952: 924:, various measurements from 873:{\displaystyle -i{\vec {k}}} 317:{\displaystyle \mathbf {v} } 7: 5088:List of Runge–Kutta methods 4830:Zeitschrift fĂĽr Astrophysik 4802:Zeitschrift fĂĽr Astrophysik 4425: 4411:Focusing on the inner four 2801:// a planet similar to mars 1193:object-oriented programming 589:Another possibility is the 10: 5191: 4914:Princeton University Press 4862:Cambridge University Press 3326:{\displaystyle {\vec {a}}} 891:gravitational perturbation 885:Special-case optimizations 788:{\displaystyle {\vec {k}}} 505:. In practice, the number 36: 29: 5121: 5068: 5015: 4982: 4709:The Astrophysical Journal 4672:The Astrophysical Journal 4538:10.4249/scholarpedia.3930 3201:// gravitational constant 3023: 2157: 1687: 1050:{\displaystyle \epsilon } 487:Calculation optimizations 92:for other applications). 4577:10.1093/mnras/274.4.1049 3557: 3108: 2483: 1279: 1117:Computational complexity 1109:which could account for 1037:(rather than 1/r) where 569:methods of Callahan and 537:computational complexity 368:In direct gravitational 5165:Cosmological simulation 5093:Linear multistep method 4893:1998ARA&A..36..599B 4666:Holmberg, Erik (1941). 3232:{\displaystyle t=t_{0}} 2269:{\displaystyle t_{n+1}} 2236:{\displaystyle t_{n+1}} 1161:Common boilerplate code 970:gravitational potential 906:oblateness of the Earth 595:gravitational potential 444:University of Cambridge 152:Nature of the particles 5098:General linear methods 5078:Exponential integrator 4822:von Hoerner, Sebastian 4798:von Hoerner, Sebastian 4422: 3549: 3535:which continues while 3522: 3425: 3327: 3282: 3233: 3100: 3077: 3050: 2460: 2423:Without acceleration, 2415: 2297: 2270: 2237: 2204: 2147: 2109: 2066: 2028: 1985: 1947: 1904: 1866: 1832: 1794: 1760: 1722: 1264: 1185: 1051: 1029: 874: 839: 789: 758: 685:fast Fourier transform 677: 647: 418: 365: 318: 294: 177:Dark matter simulation 136:from the influence of 59: 5170:Computational physics 5129:Symplectic integrator 5113:Gauss–Legendre method 4485:Barnes–Hut simulation 4421: 3550: 3523: 3426: 3328: 3283: 3234: 3101: 3078: 3051: 3049:{\displaystyle t_{0}} 2481:command may be used: 2461: 2416: 2298: 2296:{\displaystyle t_{n}} 2271: 2238: 2205: 2203:{\displaystyle t_{n}} 2148: 2146:{\displaystyle \left} 2110: 2067: 2065:{\displaystyle \left} 2029: 1986: 1984:{\displaystyle \left} 1948: 1905: 1903:{\displaystyle \left} 1867: 1833: 1831:{\displaystyle \left} 1795: 1761: 1759:{\displaystyle \left} 1723: 1265: 1186: 1052: 1030: 875: 840: 790: 759: 678: 676:{\displaystyle \rho } 648: 553:Barnes–Hut simulation 511:Millennium simulation 428:Sebastian von Hoerner 419: 359: 340:Direct gravitational 319: 295: 77:is a simulation of a 53: 5070:Higher-order methods 5060:Leapfrog integration 5017:Second-order methods 3539: 3437: 3340: 3308: 3246: 3210: 3087: 3060: 3033: 2427: 2309: 2280: 2247: 2214: 2187: 2119: 2077: 2038: 1996: 1957: 1915: 1876: 1865:{\textstyle e_{2}=z} 1843: 1804: 1793:{\textstyle e_{1}=y} 1771: 1732: 1721:{\textstyle e_{0}=x} 1699: 1217: 1184:{\textstyle n\geq 3} 1169: 1041: 978: 972:of each particle as 932:Two-particle systems 849: 799: 770: 697: 667: 606: 591:particle mesh method 585:Particle mesh method 522:leapfrog integration 417:{\displaystyle O(N)} 399: 306: 193: 43:Multibody simulation 5083:Runge–Kutta methods 5055:Newmark-beta method 5002:Semi-implicit Euler 4984:First-order methods 4842:1963ZA.....57...47V 4814:1960ZA.....50..184V 4731:1997ApJ...490..493N 4684:1941ApJ....94..385H 4627:2010MNRAS.403.1859J 4529:2008SchpJ...3.3930T 2172:equations of motion 1195:languages, such as 1156:Example simulations 526:Runge–Kutta methods 472:comoving coordinate 334:perturbation theory 330:Friedmann equations 126:structure formation 5150:Physical cosmology 5040:Beeman's algorithm 5025:Verlet integration 4850:Aarseth, Sverre J. 4423: 3545: 3518: 3421: 3323: 3278: 3229: 3099:{\displaystyle dt} 3096: 3073: 3046: 2456: 2411: 2293: 2266: 2233: 2200: 2143: 2105: 2062: 2024: 1981: 1943: 1900: 1862: 1828: 1790: 1756: 1718: 1260: 1181: 1047: 1025: 918:Lyapunov stability 889:Several different 870: 835: 785: 754: 673: 643: 462:in establishing a 460:general relativity 414: 366: 326:Poisson's Equation 314: 290: 186:Boltzmann equation 118:physical cosmology 60: 5137: 5136: 5007:Exponential Euler 4923:978-0-691-08445-9 4910:Galactic Dynamics 4871:978-0-521-12153-8 3548:{\displaystyle t} 3500: 3478: 3450: 3403: 3375: 3353: 3320: 3275: 3070: 2440: 2386: 2357: 2322: 2102: 2021: 1940: 1257: 1243: 1229: 1069:-body simulations 1020: 1019: 867: 829: 811: 782: 749: 737: 709: 661:Newton's constant 503:Newtonian gravity 357: 344:-body simulations 279: 237: 214: 167:Avogadro constant 16:(Redirected from 5182: 5035:Trapezoidal rule 4969: 4962: 4955: 4946: 4945: 4940: 4927: 4904: 4875: 4845: 4817: 4784: 4783: 4781: 4765: 4759: 4758: 4724: 4722:astro-ph/9611107 4704: 4698: 4697: 4695: 4663: 4657: 4656: 4638: 4620: 4611:(4): 1859–1872. 4596: 4590: 4589: 4579: 4569: 4567:astro-ph/9408057 4549: 4543: 4542: 4540: 4508: 4480:Virgo Consortium 4459: 4442: 4437: 4436: 4407: 4404: 4401: 4398: 4395: 4392: 4389: 4386: 4383: 4380: 4377: 4374: 4373:orbital_entities 4371: 4368: 4365: 4362: 4361:orbital_entities 4359: 4356: 4353: 4350: 4347: 4344: 4343:orbital_entities 4341: 4338: 4335: 4332: 4331:orbital_entities 4329: 4326: 4323: 4320: 4317: 4314: 4313:orbital_entities 4311: 4308: 4305: 4302: 4301:orbital_entities 4299: 4296: 4293: 4290: 4287: 4284: 4281: 4278: 4275: 4272: 4269: 4266: 4263: 4260: 4257: 4254: 4251: 4248: 4245: 4242: 4239: 4236: 4233: 4230: 4227: 4224: 4221: 4218: 4217:orbital_entities 4215: 4212: 4209: 4206: 4203: 4200: 4197: 4194: 4191: 4188: 4187:orbital_entities 4185: 4182: 4179: 4176: 4173: 4170: 4167: 4164: 4161: 4158: 4157:orbital_entities 4155: 4152: 4149: 4146: 4143: 4140: 4137: 4134: 4131: 4128: 4125: 4122: 4119: 4116: 4113: 4110: 4107: 4104: 4101: 4098: 4095: 4092: 4089: 4086: 4083: 4080: 4077: 4074: 4071: 4068: 4065: 4062: 4059: 4056: 4053: 4050: 4047: 4044: 4041: 4038: 4035: 4032: 4029: 4026: 4023: 4020: 4017: 4014: 4011: 4008: 4005: 4002: 3999: 3996: 3993: 3990: 3987: 3984: 3981: 3978: 3975: 3972: 3969: 3966: 3963: 3962:orbital_entities 3960: 3957: 3954: 3951: 3948: 3945: 3942: 3939: 3936: 3933: 3930: 3927: 3924: 3921: 3918: 3915: 3912: 3909: 3906: 3903: 3900: 3897: 3894: 3891: 3888: 3885: 3882: 3879: 3876: 3873: 3870: 3867: 3864: 3861: 3858: 3855: 3852: 3849: 3846: 3843: 3840: 3839:orbital_entities 3837: 3834: 3831: 3828: 3827:orbital_entities 3825: 3822: 3819: 3816: 3813: 3810: 3807: 3804: 3803:orbital_entities 3801: 3798: 3795: 3792: 3791:orbital_entities 3789: 3786: 3783: 3780: 3777: 3774: 3771: 3768: 3767:orbital_entities 3765: 3762: 3759: 3756: 3755:orbital_entities 3753: 3750: 3747: 3744: 3741: 3738: 3735: 3732: 3729: 3726: 3723: 3720: 3717: 3714: 3711: 3708: 3705: 3702: 3699: 3696: 3693: 3690: 3687: 3684: 3681: 3678: 3675: 3672: 3669: 3666: 3663: 3660: 3657: 3654: 3651: 3648: 3645: 3642: 3639: 3636: 3633: 3630: 3627: 3624: 3621: 3618: 3615: 3612: 3609: 3606: 3603: 3600: 3597: 3594: 3591: 3588: 3585: 3582: 3579: 3576: 3573: 3570: 3567: 3564: 3561: 3554: 3552: 3551: 3546: 3527: 3525: 3524: 3519: 3508: 3507: 3502: 3501: 3493: 3486: 3485: 3480: 3479: 3471: 3464: 3463: 3452: 3451: 3443: 3430: 3428: 3427: 3422: 3411: 3410: 3405: 3404: 3396: 3389: 3388: 3377: 3376: 3368: 3361: 3360: 3355: 3354: 3346: 3332: 3330: 3329: 3324: 3322: 3321: 3313: 3287: 3285: 3284: 3279: 3277: 3276: 3273: 3258: 3257: 3238: 3236: 3235: 3230: 3228: 3227: 3202: 3199: 3196: 3193: 3190: 3187: 3184: 3181: 3178: 3175: 3172: 3169: 3166: 3163: 3160: 3157: 3154: 3151: 3148: 3145: 3142: 3139: 3136: 3133: 3130: 3127: 3124: 3121: 3118: 3115: 3112: 3105: 3103: 3102: 3097: 3082: 3080: 3079: 3074: 3072: 3071: 3068: 3055: 3053: 3052: 3047: 3045: 3044: 3027: 3026: 3018: 3015: 3012: 3009: 3006: 3003: 3000: 2997: 2994: 2991: 2988: 2985: 2982: 2979: 2976: 2973: 2970: 2967: 2966:orbital_entities 2964: 2961: 2958: 2955: 2952: 2949: 2946: 2943: 2940: 2937: 2934: 2931: 2928: 2925: 2922: 2919: 2916: 2913: 2912:orbital_entities 2910: 2907: 2904: 2901: 2898: 2895: 2892: 2889: 2886: 2883: 2880: 2877: 2874: 2871: 2868: 2865: 2862: 2859: 2858:orbital_entities 2856: 2853: 2850: 2847: 2844: 2841: 2838: 2835: 2832: 2829: 2826: 2823: 2820: 2817: 2814: 2811: 2808: 2805: 2804:orbital_entities 2802: 2799: 2796: 2793: 2790: 2787: 2784: 2781: 2778: 2775: 2772: 2769: 2766: 2763: 2760: 2757: 2754: 2751: 2750:orbital_entities 2748: 2745: 2742: 2739: 2736: 2733: 2730: 2727: 2724: 2721: 2718: 2715: 2712: 2709: 2706: 2703: 2700: 2697: 2696:orbital_entities 2694: 2691: 2688: 2685: 2682: 2679: 2676: 2673: 2670: 2667: 2664: 2661: 2658: 2655: 2652: 2649: 2646: 2643: 2642:orbital_entities 2640: 2637: 2634: 2631: 2628: 2625: 2622: 2619: 2616: 2613: 2610: 2607: 2604: 2601: 2598: 2595: 2592: 2589: 2588:orbital_entities 2586: 2583: 2580: 2577: 2574: 2571: 2568: 2565: 2562: 2559: 2556: 2553: 2550: 2547: 2544: 2541: 2538: 2535: 2534:orbital_entities 2532: 2529: 2526: 2523: 2520: 2517: 2514: 2511: 2508: 2505: 2502: 2499: 2496: 2493: 2492:orbital_entities 2490: 2487: 2465: 2463: 2462: 2457: 2455: 2454: 2453: 2452: 2442: 2441: 2433: 2420: 2418: 2417: 2412: 2401: 2400: 2399: 2398: 2388: 2387: 2379: 2372: 2371: 2370: 2369: 2359: 2358: 2350: 2343: 2342: 2341: 2340: 2324: 2323: 2315: 2302: 2300: 2299: 2294: 2292: 2291: 2275: 2273: 2272: 2267: 2265: 2264: 2242: 2240: 2239: 2234: 2232: 2231: 2209: 2207: 2206: 2201: 2199: 2198: 2161: 2160: 2152: 2150: 2149: 2144: 2142: 2138: 2114: 2112: 2111: 2106: 2104: 2103: 2095: 2089: 2088: 2071: 2069: 2068: 2063: 2061: 2057: 2033: 2031: 2030: 2025: 2023: 2022: 2014: 2008: 2007: 1990: 1988: 1987: 1982: 1980: 1976: 1952: 1950: 1949: 1944: 1942: 1941: 1933: 1927: 1926: 1909: 1907: 1906: 1901: 1899: 1895: 1871: 1869: 1868: 1863: 1855: 1854: 1837: 1835: 1834: 1829: 1827: 1823: 1799: 1797: 1796: 1791: 1783: 1782: 1765: 1763: 1762: 1757: 1755: 1751: 1727: 1725: 1724: 1719: 1711: 1710: 1691: 1690: 1682: 1679: 1676: 1673: 1670: 1667: 1664: 1661: 1658: 1655: 1652: 1649: 1646: 1643: 1640: 1637: 1634: 1631: 1628: 1625: 1622: 1619: 1616: 1613: 1610: 1607: 1604: 1601: 1598: 1595: 1592: 1589: 1586: 1583: 1580: 1577: 1574: 1571: 1568: 1565: 1562: 1559: 1556: 1553: 1550: 1547: 1544: 1541: 1538: 1535: 1532: 1529: 1526: 1523: 1520: 1517: 1514: 1511: 1508: 1505: 1502: 1499: 1496: 1493: 1490: 1487: 1484: 1481: 1478: 1475: 1472: 1469: 1466: 1463: 1460: 1457: 1454: 1451: 1448: 1445: 1442: 1439: 1436: 1433: 1430: 1427: 1424: 1421: 1418: 1415: 1412: 1409: 1406: 1403: 1400: 1397: 1394: 1391: 1388: 1385: 1382: 1379: 1376: 1373: 1370: 1367: 1364: 1361: 1358: 1355: 1352: 1349: 1346: 1343: 1340: 1337: 1334: 1331: 1328: 1325: 1322: 1319: 1316: 1313: 1310: 1307: 1304: 1301: 1298: 1295: 1292: 1289: 1286: 1283: 1269: 1267: 1266: 1261: 1259: 1258: 1250: 1244: 1236: 1231: 1230: 1222: 1201:boilerplate code 1190: 1188: 1187: 1182: 1107:galaxy formation 1090:cold dark matter 1056: 1054: 1053: 1048: 1034: 1032: 1031: 1026: 1021: 1018: 1017: 1005: 1004: 995: 991: 879: 877: 876: 871: 869: 868: 860: 844: 842: 841: 836: 831: 830: 822: 813: 812: 804: 794: 792: 791: 786: 784: 783: 775: 763: 761: 760: 755: 750: 748: 747: 738: 730: 728: 711: 710: 702: 689:frequency domain 682: 680: 679: 674: 652: 650: 649: 644: 638: 618: 617: 599:Poisson equation 573:yield optimal O( 480:speed of gravity 425: 423: 421: 420: 415: 390:Lund Observatory 358: 323: 321: 320: 315: 313: 302:In the equation, 299: 297: 296: 291: 280: 278: 277: 268: 260: 246: 238: 236: 228: 220: 215: 213: 205: 197: 164: 130:galaxy filaments 79:dynamical system 75:-body simulation 39:Multibody system 21: 5190: 5189: 5185: 5184: 5183: 5181: 5180: 5179: 5140: 5139: 5138: 5133: 5117: 5064: 5045:Midpoint method 5030:Velocity Verlet 5011: 4978: 4973: 4924: 4872: 4793: 4791:Further reading 4788: 4787: 4766: 4762: 4705: 4701: 4664: 4660: 4597: 4593: 4550: 4546: 4509: 4505: 4500: 4457: 4438: 4431: 4428: 4409: 4408: 4405: 4402: 4399: 4396: 4393: 4390: 4387: 4384: 4381: 4378: 4375: 4372: 4369: 4366: 4363: 4360: 4357: 4354: 4351: 4348: 4345: 4342: 4339: 4336: 4333: 4330: 4327: 4324: 4321: 4318: 4315: 4312: 4309: 4306: 4303: 4300: 4297: 4294: 4291: 4288: 4285: 4282: 4279: 4276: 4273: 4270: 4267: 4264: 4261: 4258: 4255: 4252: 4249: 4246: 4243: 4240: 4237: 4234: 4231: 4228: 4225: 4222: 4219: 4216: 4213: 4210: 4207: 4204: 4201: 4198: 4195: 4192: 4189: 4186: 4183: 4180: 4177: 4174: 4171: 4168: 4165: 4162: 4159: 4156: 4153: 4150: 4147: 4144: 4141: 4138: 4135: 4132: 4129: 4126: 4123: 4120: 4117: 4114: 4111: 4108: 4105: 4102: 4099: 4096: 4093: 4090: 4087: 4084: 4081: 4078: 4075: 4072: 4069: 4066: 4063: 4060: 4057: 4054: 4051: 4048: 4045: 4042: 4039: 4036: 4033: 4030: 4027: 4024: 4021: 4018: 4015: 4012: 4009: 4006: 4003: 4000: 3997: 3994: 3991: 3988: 3985: 3982: 3979: 3976: 3973: 3970: 3967: 3964: 3961: 3958: 3955: 3952: 3949: 3946: 3943: 3940: 3937: 3934: 3931: 3928: 3925: 3922: 3919: 3916: 3913: 3910: 3907: 3904: 3901: 3898: 3895: 3892: 3889: 3886: 3883: 3880: 3877: 3874: 3871: 3868: 3865: 3862: 3859: 3856: 3853: 3850: 3847: 3844: 3841: 3838: 3835: 3832: 3829: 3826: 3823: 3820: 3817: 3814: 3811: 3808: 3805: 3802: 3799: 3796: 3793: 3790: 3787: 3784: 3781: 3778: 3775: 3772: 3769: 3766: 3763: 3760: 3757: 3754: 3751: 3748: 3745: 3742: 3739: 3736: 3733: 3730: 3727: 3724: 3721: 3718: 3715: 3712: 3709: 3706: 3703: 3700: 3697: 3694: 3691: 3688: 3685: 3682: 3679: 3676: 3673: 3670: 3667: 3664: 3661: 3658: 3655: 3652: 3649: 3646: 3643: 3640: 3637: 3634: 3631: 3628: 3625: 3622: 3619: 3616: 3613: 3610: 3607: 3604: 3601: 3598: 3595: 3592: 3589: 3586: 3583: 3580: 3577: 3574: 3571: 3568: 3565: 3562: 3559: 3540: 3537: 3536: 3503: 3492: 3491: 3490: 3481: 3470: 3469: 3468: 3453: 3442: 3441: 3440: 3438: 3435: 3434: 3406: 3395: 3394: 3393: 3378: 3367: 3366: 3365: 3356: 3345: 3344: 3343: 3341: 3338: 3337: 3312: 3311: 3309: 3306: 3305: 3294: 3272: 3268: 3253: 3249: 3247: 3244: 3243: 3223: 3219: 3211: 3208: 3207: 3204: 3203: 3200: 3197: 3194: 3191: 3188: 3185: 3182: 3179: 3176: 3173: 3170: 3167: 3164: 3161: 3158: 3155: 3152: 3149: 3146: 3143: 3140: 3137: 3134: 3131: 3128: 3125: 3122: 3119: 3116: 3113: 3110: 3088: 3085: 3084: 3067: 3063: 3061: 3058: 3057: 3040: 3036: 3034: 3031: 3030: 3024: 3020: 3019: 3016: 3013: 3010: 3007: 3004: 3001: 2998: 2995: 2992: 2989: 2986: 2983: 2980: 2977: 2974: 2971: 2968: 2965: 2962: 2959: 2956: 2953: 2950: 2947: 2944: 2941: 2938: 2935: 2932: 2929: 2926: 2923: 2920: 2917: 2914: 2911: 2908: 2905: 2902: 2899: 2896: 2893: 2890: 2887: 2884: 2881: 2878: 2875: 2872: 2869: 2866: 2863: 2860: 2857: 2854: 2851: 2848: 2845: 2842: 2839: 2836: 2833: 2830: 2827: 2824: 2821: 2818: 2815: 2812: 2809: 2806: 2803: 2800: 2797: 2794: 2791: 2788: 2785: 2782: 2779: 2776: 2773: 2770: 2767: 2764: 2761: 2758: 2755: 2752: 2749: 2746: 2743: 2740: 2737: 2734: 2731: 2728: 2725: 2722: 2719: 2716: 2713: 2710: 2707: 2704: 2701: 2698: 2695: 2692: 2689: 2686: 2683: 2680: 2677: 2674: 2671: 2668: 2665: 2662: 2659: 2656: 2653: 2650: 2647: 2644: 2641: 2638: 2635: 2632: 2629: 2626: 2623: 2620: 2617: 2614: 2611: 2608: 2605: 2602: 2599: 2596: 2593: 2590: 2587: 2584: 2581: 2578: 2575: 2572: 2569: 2566: 2563: 2560: 2557: 2554: 2551: 2548: 2545: 2542: 2539: 2536: 2533: 2530: 2527: 2524: 2521: 2518: 2515: 2512: 2509: 2506: 2503: 2500: 2497: 2494: 2491: 2488: 2485: 2471:semi-major axes 2448: 2444: 2443: 2432: 2431: 2430: 2428: 2425: 2424: 2394: 2390: 2389: 2378: 2377: 2376: 2365: 2361: 2360: 2349: 2348: 2347: 2330: 2326: 2325: 2314: 2313: 2312: 2310: 2307: 2306: 2287: 2283: 2281: 2278: 2277: 2254: 2250: 2248: 2245: 2244: 2221: 2217: 2215: 2212: 2211: 2194: 2190: 2188: 2185: 2184: 2168: 2158: 2126: 2122: 2120: 2117: 2116: 2094: 2093: 2084: 2080: 2078: 2075: 2074: 2045: 2041: 2039: 2036: 2035: 2013: 2012: 2003: 1999: 1997: 1994: 1993: 1964: 1960: 1958: 1955: 1954: 1932: 1931: 1922: 1918: 1916: 1913: 1912: 1883: 1879: 1877: 1874: 1873: 1850: 1846: 1844: 1841: 1840: 1811: 1807: 1805: 1802: 1801: 1778: 1774: 1772: 1769: 1768: 1739: 1735: 1733: 1730: 1729: 1706: 1702: 1700: 1697: 1696: 1688: 1684: 1683: 1680: 1677: 1674: 1671: 1668: 1665: 1662: 1659: 1656: 1653: 1650: 1647: 1644: 1641: 1638: 1635: 1632: 1629: 1626: 1623: 1620: 1617: 1614: 1611: 1608: 1605: 1602: 1599: 1596: 1593: 1590: 1587: 1584: 1581: 1578: 1575: 1572: 1569: 1566: 1563: 1560: 1557: 1554: 1551: 1548: 1545: 1542: 1539: 1536: 1533: 1530: 1527: 1524: 1521: 1518: 1515: 1512: 1509: 1506: 1503: 1500: 1497: 1494: 1491: 1488: 1485: 1482: 1479: 1476: 1473: 1470: 1467: 1464: 1461: 1458: 1455: 1452: 1449: 1446: 1443: 1440: 1437: 1434: 1431: 1428: 1425: 1422: 1419: 1416: 1413: 1410: 1407: 1404: 1401: 1398: 1395: 1392: 1389: 1386: 1383: 1380: 1377: 1374: 1371: 1368: 1365: 1362: 1359: 1356: 1353: 1350: 1347: 1344: 1341: 1338: 1335: 1332: 1329: 1326: 1323: 1320: 1317: 1314: 1311: 1308: 1305: 1302: 1299: 1296: 1293: 1290: 1287: 1284: 1281: 1249: 1248: 1235: 1221: 1220: 1218: 1215: 1214: 1170: 1167: 1166: 1163: 1158: 1119: 1086: 1071: 1042: 1039: 1038: 1013: 1009: 1000: 996: 990: 979: 976: 975: 955: 934: 887: 859: 858: 850: 847: 846: 821: 820: 803: 802: 800: 797: 796: 774: 773: 771: 768: 767: 743: 739: 729: 727: 701: 700: 698: 695: 694: 668: 665: 664: 634: 613: 609: 607: 604: 603: 587: 577: log  545: 489: 456: 400: 397: 396: 394: 348: 346: 309: 307: 304: 303: 273: 269: 261: 259: 242: 229: 221: 219: 206: 198: 196: 194: 191: 190: 179: 162: 154: 46: 35: 28: 23: 22: 15: 12: 11: 5: 5188: 5178: 5177: 5172: 5167: 5162: 5157: 5152: 5135: 5134: 5132: 5131: 5125: 5123: 5119: 5118: 5116: 5115: 5110: 5105: 5100: 5095: 5090: 5085: 5080: 5074: 5072: 5066: 5065: 5063: 5062: 5057: 5052: 5047: 5042: 5037: 5032: 5027: 5021: 5019: 5013: 5012: 5010: 5009: 5004: 4999: 4997:Backward Euler 4994: 4988: 4986: 4980: 4979: 4972: 4971: 4964: 4957: 4949: 4943: 4942: 4928: 4922: 4905: 4887:(1): 599–654. 4876: 4870: 4854:Gravitational 4846: 4818: 4792: 4789: 4786: 4785: 4779:10.1.1.38.6242 4760: 4739:10.1086/304888 4715:(2): 493–508. 4699: 4693:10.1086/144344 4678:(3): 385–395. 4658: 4591: 4544: 4502: 4501: 4499: 4496: 4495: 4494: 4488: 4482: 4477: 4471: 4466: 4460: 4451: 4448:Millennium Run 4444: 4443: 4440:Physics portal 4427: 4424: 3558: 3544: 3529: 3528: 3517: 3514: 3511: 3506: 3499: 3496: 3489: 3484: 3477: 3474: 3467: 3462: 3459: 3456: 3449: 3446: 3431: 3420: 3417: 3414: 3409: 3402: 3399: 3392: 3387: 3384: 3381: 3374: 3371: 3364: 3359: 3352: 3349: 3334: 3319: 3316: 3302: 3293: 3290: 3271: 3267: 3264: 3261: 3256: 3252: 3226: 3222: 3218: 3215: 3109: 3095: 3092: 3066: 3043: 3039: 2484: 2451: 2447: 2439: 2436: 2410: 2407: 2404: 2397: 2393: 2385: 2382: 2375: 2368: 2364: 2356: 2353: 2346: 2339: 2336: 2333: 2329: 2321: 2318: 2290: 2286: 2263: 2260: 2257: 2253: 2230: 2227: 2224: 2220: 2197: 2193: 2167: 2164: 2156:Additionally, 2154: 2153: 2141: 2137: 2133: 2129: 2125: 2101: 2098: 2092: 2087: 2083: 2072: 2060: 2056: 2052: 2048: 2044: 2020: 2017: 2011: 2006: 2002: 1991: 1979: 1975: 1971: 1967: 1963: 1939: 1936: 1930: 1925: 1921: 1910: 1898: 1894: 1890: 1886: 1882: 1861: 1858: 1853: 1849: 1838: 1826: 1822: 1818: 1814: 1810: 1789: 1786: 1781: 1777: 1766: 1754: 1750: 1746: 1742: 1738: 1717: 1714: 1709: 1705: 1280: 1256: 1253: 1247: 1242: 1239: 1234: 1228: 1225: 1180: 1177: 1174: 1162: 1159: 1157: 1154: 1118: 1115: 1085: 1082: 1070: 1063: 1046: 1024: 1016: 1012: 1008: 1003: 999: 994: 989: 986: 983: 954: 951: 933: 930: 926:ergodic theory 886: 883: 866: 863: 857: 854: 834: 828: 825: 819: 816: 810: 807: 781: 778: 753: 746: 742: 736: 733: 726: 723: 720: 717: 714: 708: 705: 672: 641: 637: 633: 630: 627: 624: 621: 616: 612: 586: 583: 544: 541: 488: 485: 455: 452: 440:Sverre Aarseth 413: 410: 407: 404: 345: 338: 312: 289: 286: 283: 276: 272: 267: 264: 258: 255: 252: 249: 245: 241: 235: 232: 227: 224: 218: 212: 209: 204: 201: 178: 175: 153: 150: 26: 9: 6: 4: 3: 2: 5187: 5176: 5173: 5171: 5168: 5166: 5163: 5161: 5158: 5156: 5153: 5151: 5148: 5147: 5145: 5130: 5127: 5126: 5124: 5120: 5114: 5111: 5109: 5106: 5104: 5101: 5099: 5096: 5094: 5091: 5089: 5086: 5084: 5081: 5079: 5076: 5075: 5073: 5071: 5067: 5061: 5058: 5056: 5053: 5051: 5050:Heun's method 5048: 5046: 5043: 5041: 5038: 5036: 5033: 5031: 5028: 5026: 5023: 5022: 5020: 5018: 5014: 5008: 5005: 5003: 5000: 4998: 4995: 4993: 4990: 4989: 4987: 4985: 4981: 4977: 4970: 4965: 4963: 4958: 4956: 4951: 4950: 4947: 4938: 4934: 4929: 4925: 4919: 4915: 4911: 4906: 4902: 4898: 4894: 4890: 4886: 4882: 4877: 4873: 4867: 4863: 4859: 4855: 4851: 4847: 4843: 4839: 4835: 4832:(in German). 4831: 4827: 4823: 4819: 4815: 4811: 4807: 4804:(in German). 4803: 4799: 4795: 4794: 4780: 4775: 4771: 4764: 4756: 4752: 4748: 4744: 4740: 4736: 4732: 4728: 4723: 4718: 4714: 4710: 4703: 4694: 4689: 4685: 4681: 4677: 4673: 4669: 4662: 4654: 4650: 4646: 4642: 4637: 4632: 4628: 4624: 4619: 4614: 4610: 4606: 4602: 4595: 4587: 4583: 4578: 4573: 4568: 4563: 4559: 4555: 4548: 4539: 4534: 4530: 4526: 4522: 4518: 4514: 4507: 4503: 4492: 4489: 4486: 4483: 4481: 4478: 4475: 4474:Natural units 4472: 4470: 4467: 4464: 4461: 4455: 4452: 4449: 4446: 4445: 4441: 4435: 4430: 4420: 4416: 4414: 4413:rocky planets 4139:r_unit_vector 4109:r_unit_vector 4079:r_unit_vector 3998:r_unit_vector 3556: 3542: 3534: 3515: 3509: 3504: 3494: 3487: 3482: 3472: 3465: 3460: 3457: 3454: 3444: 3432: 3418: 3412: 3407: 3397: 3390: 3385: 3382: 3379: 3369: 3362: 3357: 3347: 3335: 3314: 3303: 3300: 3299: 3298: 3289: 3269: 3265: 3262: 3259: 3254: 3250: 3240: 3224: 3220: 3216: 3213: 3107: 3093: 3090: 3064: 3041: 3037: 2510:OrbitalEntity 2486:OrbitalEntity 2482: 2480: 2476: 2472: 2467: 2449: 2445: 2434: 2421: 2408: 2402: 2395: 2391: 2380: 2373: 2366: 2362: 2351: 2344: 2337: 2334: 2331: 2327: 2316: 2304: 2288: 2284: 2261: 2258: 2255: 2251: 2228: 2225: 2222: 2218: 2195: 2191: 2182: 2177: 2173: 2163: 2159:OrbitalEntity 2139: 2135: 2131: 2127: 2123: 2099: 2096: 2090: 2085: 2081: 2073: 2058: 2054: 2050: 2046: 2042: 2018: 2015: 2009: 2004: 2000: 1992: 1977: 1973: 1969: 1965: 1961: 1937: 1934: 1928: 1923: 1919: 1911: 1896: 1892: 1888: 1884: 1880: 1859: 1856: 1851: 1847: 1839: 1824: 1820: 1816: 1812: 1808: 1787: 1784: 1779: 1775: 1767: 1752: 1748: 1744: 1740: 1736: 1715: 1712: 1707: 1703: 1695: 1694: 1693: 1689:OrbitalEntity 1480:OrbitalEntity 1468:OrbitalEntity 1456:OrbitalEntity 1432:OrbitalEntity 1278: 1275: 1270: 1251: 1245: 1240: 1237: 1232: 1223: 1212: 1210: 1206: 1205:state vectors 1202: 1198: 1194: 1178: 1175: 1172: 1153: 1151: 1147: 1142: 1140: 1136: 1132: 1128: 1124: 1114: 1112: 1108: 1103: 1099: 1095: 1091: 1081: 1079: 1075: 1068: 1065:Results from 1062: 1060: 1044: 1035: 1022: 1014: 1010: 1006: 1001: 997: 992: 987: 984: 973: 971: 967: 963: 959: 950: 947: 943: 939: 929: 927: 923: 922:Lyapunov time 919: 913: 909: 907: 903: 898: 896: 892: 882: 861: 855: 852: 817: 814: 805: 776: 764: 751: 744: 740: 731: 724: 721: 718: 715: 712: 692: 690: 686: 670: 662: 658: 653: 639: 635: 631: 628: 625: 622: 614: 601: 600: 596: 592: 582: 580: 576: 572: 568: 563: 558: 554: 550: 540: 538: 533: 529: 527: 523: 518: 516: 512: 508: 504: 500: 497: 493: 484: 481: 477: 473: 469: 465: 461: 451: 449: 445: 441: 437: 433: 429: 408: 402: 391: 387: 386:Erik Holmberg 383: 378: 375: 371: 363: 343: 337: 335: 331: 327: 300: 281: 265: 256: 253: 247: 239: 233: 225: 216: 210: 207: 202: 199: 188: 187: 183: 174: 172: 168: 160: 149: 147: 146:star clusters 143: 139: 135: 131: 127: 123: 119: 115: 111: 107: 103: 99: 95: 91: 90:-body problem 89: 84: 80: 76: 74: 69: 65: 57: 52: 48: 44: 40: 33: 32:GM N platform 19: 4992:Euler method 4936: 4932: 4909: 4884: 4880: 4857: 4853: 4833: 4829: 4825: 4805: 4801: 4769: 4763: 4712: 4708: 4702: 4675: 4671: 4661: 4608: 4604: 4594: 4557: 4547: 4520: 4517:Scholarpedia 4516: 4506: 4410: 4133:acceleration 4103:acceleration 4073:acceleration 3941:acceleration 3530: 3295: 3241: 3205: 3021: 2475:Memory space 2468: 2422: 2305: 2180: 2175: 2169: 2155: 1685: 1271: 1213: 1164: 1145: 1143: 1134: 1130: 1126: 1122: 1120: 1087: 1073: 1072: 1066: 1036: 974: 957: 956: 938:solar masses 935: 914: 910: 902:frozen orbit 899: 895:Solar System 888: 765: 693: 656: 654: 602: 588: 578: 574: 551:, such as a 549:tree methods 548: 546: 543:Tree methods 534: 530: 519: 514: 506: 495: 491: 490: 468:scale factor 457: 447: 381: 379: 373: 369: 367: 362:Solar System 341: 301: 189: 180: 155: 141: 134:galaxy halos 121: 98:astrophysics 93: 87: 72: 71: 61: 55: 47: 4523:(5): 3930. 4283:N_ASTEROIDS 3695:N_ASTEROIDS 3614:N_ASTEROIDS 3292:Propagation 3025:N_ASTEROIDS 2528:N_ASTEROIDS 1207:, and thus 1150:ray tracing 1111:galaxy bias 1061:realistic. 1059:simulations 962:divergences 476:redshifting 438:, Germany. 182:Dark matter 138:dark matter 5160:Simulation 5144:Categories 4498:References 4289:entity_idx 4271:entity_idx 4259:entity_idx 3533:while loop 3011:102.413e24 2975:4495.060e9 2921:2872.463e9 2867:1433.529e9 2849:1898.19e24 2795:0.64171e24 2633:0.33011e24 1686:Note that 1146:eventually 436:Heidelberg 5175:Particles 4774:CiteSeerX 4755:0004-637X 4747:1538-4357 4653:0035-8711 4645:1365-2966 4618:0910.0258 4586:1365-2966 3513:Δ 3510:⋅ 3498:→ 3476:→ 3448:→ 3416:Δ 3413:⋅ 3401:→ 3383:− 3373:→ 3351:→ 3318:→ 3260:≤ 2957:86.813e24 2903:568.34e24 2813:778.570e9 2759:227.923e9 2741:5.9724e24 2705:149.596e9 2687:4.8675e24 2651:108.209e9 2438:→ 2406:Δ 2403:⋅ 2384:→ 2355:→ 2320:→ 2100:˙ 2019:˙ 1938:˙ 1255:→ 1246:∑ 1227:→ 1176:≥ 1045:ϵ 1011:ϵ 988:− 982:Φ 958:Softening 953:Softening 865:→ 853:− 833:Φ 827:→ 824:∇ 818:− 809:→ 780:→ 735:^ 732:ρ 722:π 716:− 707:^ 704:Φ 671:ρ 636:ρ 629:π 620:Φ 611:∇ 562:multipole 288:Φ 285:∇ 282:⋅ 271:∂ 263:∂ 257:− 251:∇ 248:⋅ 231:∂ 223:∂ 159:gas cloud 140:. Direct 68:astronomy 18:Softening 4852:(2003). 4426:See also 4043:r_vector 4025:r_vector 4007:r_vector 3926:r_vector 3914:r_vector 3902:r_vector 3890:r_vector 3878:r_vector 3866:r_vector 3815:r_vector 3779:r_vector 3743:r_vector 3737:r_vector 3195:6.67e-11 2597:57.909e9 2579:1.989e30 1274:scalable 1137:) is in 946:softened 571:Kosaraju 128:such as 5155:Gravity 5108:Yoshida 4889:Bibcode 4838:Bibcode 4810:Bibcode 4808:: 184. 4727:Bibcode 4680:Bibcode 4623:Bibcode 4525:Bibcode 3995:Vector3 3734:Vector3 3632:Vector3 2783:24.07e3 2729:29.78e3 2675:35.02e3 2621:47.36e3 1333:Vector3 1321:Vector3 1309:Vector3 1285:Vector3 1209:vectors 1199:, some 1102:photons 1098:leptons 1094:baryons 1078:baryons 928:, etc. 470:) in a 442:at the 430:at the 424:⁠ 395:⁠ 388:at the 364:planets 83:gravity 64:physics 5122:Theory 4939:. ACM. 4920:  4868:  4836:: 47. 4776:  4753:  4745:  4651:  4643:  4584:  4463:GADGET 4256:size_t 3938:double 3851:double 3725:m1_idx 3719:m2_idx 3701:m2_idx 3683:m2_idx 3671:m2_idx 3668:size_t 3620:m1_idx 3602:m1_idx 3590:m1_idx 3587:size_t 3186:double 3156:double 3141:double 3126:double 3111:double 3022:where 2999:5.43e3 2945:6.80e3 2891:9.68e3 2504:sizeof 2498:malloc 2479:malloc 2176:forces 1540:double 1531:double 1522:double 1513:double 1504:double 1495:double 1486:double 1477:inline 1438:double 1429:struct 1357:double 1348:double 1339:double 1330:inline 1291:double 1282:struct 1139:PSPACE 942:binary 766:where 655:where 557:octree 4743:eISSN 4717:arXiv 4641:eISSN 4613:arXiv 4582:eISSN 4562:arXiv 4055:r_mag 4037:r_mag 4019:r_mag 3983:r_mag 3953:BIG_G 3854:r_mag 3572:t_end 3560:while 3189:BIG_G 3165:86400 3159:t_end 3150:86400 2181:steps 1663:-> 1645:-> 1627:-> 1609:-> 1591:-> 1573:-> 1555:-> 1408:-> 1390:-> 1372:-> 966:force 555:, an 116:. In 102:Earth 85:(see 70:, an 4918:ISBN 4866:ISBN 4751:ISSN 4649:ISSN 4274:< 3947:-1.0 3860:sqrt 3686:< 3605:< 3569:< 3266:< 2837:13e3 1660:this 1642:this 1624:this 1606:this 1588:this 1570:this 1552:this 1405:this 1387:this 1369:this 1100:and 663:and 132:and 106:Moon 66:and 41:and 4897:doi 4735:doi 4713:490 4688:doi 4631:doi 4609:403 4572:doi 4533:doi 4250:for 4229:a_g 4199:a_g 4169:a_g 4121:a_g 4091:a_g 4061:a_g 3989:2.0 3977:pow 3662:for 3635:a_g 3581:for 3274:end 3171:365 3135:t_0 3114:t_0 3069:end 3056:to 3005:0.0 2993:0.0 2987:0.0 2981:0.0 2951:0.0 2939:0.0 2933:0.0 2927:0.0 2897:0.0 2885:0.0 2879:0.0 2873:0.0 2843:0.0 2831:0.0 2825:0.0 2819:0.0 2789:0.0 2777:0.0 2771:0.0 2765:0.0 2735:0.0 2723:0.0 2717:0.0 2711:0.0 2681:0.0 2669:0.0 2663:0.0 2657:0.0 2627:0.0 2615:0.0 2609:0.0 2603:0.0 2573:0.0 2567:0.0 2561:0.0 2555:0.0 2549:0.0 2543:0.0 2531:)); 1197:C++ 659:is 547:In 434:in 110:Sun 62:In 54:An 5146:: 4916:. 4912:. 4895:. 4885:36 4883:. 4864:. 4860:. 4834:57 4806:50 4749:. 4741:. 4733:. 4725:. 4711:. 4686:. 4676:94 4674:. 4670:. 4647:. 4639:. 4629:. 4621:. 4607:. 4603:. 4580:. 4570:. 4560:. 4556:. 4531:. 4519:. 4515:. 4400:dt 4397:+= 4385:dt 4370:+= 4355:dt 4340:+= 4325:dt 4310:+= 4292:++ 4241:dt 4226:+= 4211:dt 4196:+= 4181:dt 4166:+= 4130:+= 4100:+= 4070:+= 4058:}; 3992:); 3935:); 3722:!= 3713:if 3704:++ 3659:}; 3623:++ 3288:. 3239:. 3177:10 3144:dt 3014:}; 2960:}; 2906:}; 2852:}; 2798:}; 2744:}; 2690:}; 2636:}; 2582:}; 1681:}; 1672:e6 1654:e5 1636:e4 1618:e3 1600:e2 1582:e1 1564:e0 1543:e6 1534:e5 1525:e4 1516:e3 1507:e2 1498:e1 1489:e0 1474:{} 1471:() 1462:{} 1459:() 1453:}; 1426:}; 1417:e2 1399:e1 1381:e0 1360:e2 1351:e1 1342:e0 1327:{} 1324:() 1315:{} 1312:() 1306:}; 1152:. 1141:. 1113:. 1096:, 920:, 897:. 336:. 163:10 148:. 120:, 4968:e 4961:t 4954:v 4941:. 4933:k 4926:. 4903:. 4899:: 4891:: 4874:. 4856:N 4844:. 4840:: 4826:n 4816:. 4812:: 4782:. 4757:. 4737:: 4729:: 4719:: 4696:. 4690:: 4682:: 4655:. 4633:: 4625:: 4615:: 4588:. 4574:: 4564:: 4541:. 4535:: 4527:: 4521:3 4406:} 4403:; 4394:t 4391:} 4388:; 4382:* 4379:e 4376:. 4367:e 4364:. 4358:; 4352:* 4349:e 4346:. 4337:e 4334:. 4328:; 4322:* 4319:e 4316:. 4307:e 4304:. 4298:{ 4295:) 4286:; 4280:+ 4277:9 4268:; 4265:0 4262:= 4253:( 4247:} 4244:; 4238:* 4235:e 4232:. 4223:e 4220:. 4214:; 4208:* 4205:e 4202:. 4193:e 4190:. 4184:; 4178:* 4175:e 4172:. 4163:e 4160:. 4154:} 4151:} 4148:; 4145:e 4142:. 4136:* 4127:e 4124:. 4118:; 4115:e 4112:. 4106:* 4097:e 4094:. 4088:; 4085:e 4082:. 4076:* 4067:e 4064:. 4052:/ 4049:e 4046:. 4040:, 4034:/ 4031:e 4028:. 4022:, 4016:/ 4013:e 4010:. 4004:{ 4001:= 3986:, 3980:( 3974:/ 3971:) 3968:e 3965:. 3959:( 3956:* 3950:* 3944:= 3932:e 3929:. 3923:* 3920:e 3917:. 3911:+ 3908:e 3905:. 3899:* 3896:e 3893:. 3887:+ 3884:e 3881:. 3875:* 3872:e 3869:. 3863:( 3857:= 3848:; 3845:e 3842:. 3836:- 3833:e 3830:. 3824:= 3821:e 3818:. 3812:; 3809:e 3806:. 3800:- 3797:e 3794:. 3788:= 3785:e 3782:. 3776:; 3773:e 3770:. 3764:- 3761:e 3758:. 3752:= 3749:e 3746:. 3740:; 3731:{ 3728:) 3716:( 3710:{ 3707:) 3698:; 3692:+ 3689:9 3680:; 3677:0 3674:= 3665:( 3656:0 3653:, 3650:0 3647:, 3644:0 3641:{ 3638:= 3629:{ 3626:) 3617:; 3611:+ 3608:9 3599:; 3596:0 3593:= 3584:( 3578:{ 3575:) 3566:t 3563:( 3543:t 3516:t 3505:n 3495:v 3488:+ 3483:n 3473:r 3466:= 3461:1 3458:+ 3455:n 3445:r 3419:t 3408:n 3398:a 3391:+ 3386:1 3380:n 3370:v 3363:= 3358:n 3348:v 3333:) 3315:a 3270:t 3263:t 3255:0 3251:t 3225:0 3221:t 3217:= 3214:t 3198:; 3192:= 3180:; 3174:* 3168:* 3162:= 3153:; 3147:= 3138:; 3132:= 3129:t 3123:; 3120:0 3117:= 3094:t 3091:d 3065:t 3042:0 3038:t 3008:, 3002:, 2996:, 2990:, 2984:, 2978:, 2972:{ 2969:= 2954:, 2948:, 2942:, 2936:, 2930:, 2924:, 2918:{ 2915:= 2900:, 2894:, 2888:, 2882:, 2876:, 2870:, 2864:{ 2861:= 2846:, 2840:, 2834:, 2828:, 2822:, 2816:, 2810:{ 2807:= 2792:, 2786:, 2780:, 2774:, 2768:, 2762:, 2756:{ 2753:= 2738:, 2732:, 2726:, 2720:, 2714:, 2708:, 2702:{ 2699:= 2684:, 2678:, 2672:, 2666:, 2660:, 2654:, 2648:{ 2645:= 2630:, 2624:, 2618:, 2612:, 2606:, 2600:, 2594:{ 2591:= 2576:, 2570:, 2564:, 2558:, 2552:, 2546:, 2540:{ 2537:= 2525:+ 2522:9 2519:( 2516:* 2513:) 2507:( 2501:( 2495:= 2489:* 2450:n 2446:t 2435:v 2409:t 2396:n 2392:t 2381:v 2374:+ 2367:n 2363:t 2352:r 2345:= 2338:1 2335:+ 2332:n 2328:t 2317:r 2289:n 2285:t 2262:1 2259:+ 2256:n 2252:t 2229:1 2226:+ 2223:n 2219:t 2196:n 2192:t 2140:] 2136:1 2132:0 2128:0 2124:[ 2097:z 2091:= 2086:5 2082:e 2059:] 2055:0 2051:1 2047:0 2043:[ 2016:y 2010:= 2005:4 2001:e 1978:] 1974:0 1970:0 1966:1 1962:[ 1935:x 1929:= 1924:3 1920:e 1897:] 1893:1 1889:0 1885:0 1881:[ 1860:z 1857:= 1852:2 1848:e 1825:] 1821:0 1817:1 1813:0 1809:[ 1788:y 1785:= 1780:1 1776:e 1753:] 1749:0 1745:0 1741:1 1737:[ 1716:x 1713:= 1708:0 1704:e 1678:} 1675:; 1669:= 1666:e 1657:; 1651:= 1648:e 1639:; 1633:= 1630:e 1621:; 1615:= 1612:e 1603:; 1597:= 1594:e 1585:; 1579:= 1576:e 1567:; 1561:= 1558:e 1549:{ 1546:) 1537:, 1528:, 1519:, 1510:, 1501:, 1492:, 1483:( 1465:~ 1450:0 1447:{ 1444:= 1441:e 1435:{ 1423:} 1420:; 1414:= 1411:e 1402:; 1396:= 1393:e 1384:; 1378:= 1375:e 1366:{ 1363:) 1354:, 1345:, 1336:( 1318:~ 1303:0 1300:{ 1297:= 1294:e 1288:{ 1252:F 1241:m 1238:1 1233:= 1224:a 1179:3 1173:n 1135:n 1131:n 1127:n 1123:n 1074:N 1067:N 1023:, 1015:2 1007:+ 1002:2 998:r 993:1 985:= 862:k 856:i 815:= 806:g 777:k 752:, 745:2 741:k 725:G 719:4 713:= 657:G 640:, 632:G 626:4 623:= 615:2 579:n 575:n 515:N 507:N 496:N 492:N 448:N 412:) 409:N 406:( 403:O 382:N 374:N 370:N 342:N 311:v 275:v 266:f 254:f 244:v 240:+ 234:t 226:f 217:= 211:t 208:d 203:f 200:d 142:N 122:N 108:- 104:- 94:N 88:n 73:N 56:N 45:. 34:. 20:)

Index

Softening
GM N platform
Multibody system
Multibody simulation

physics
astronomy
dynamical system
gravity
n-body problem
astrophysics
Earth
Moon
Sun
large-scale structure of the universe
physical cosmology
structure formation
galaxy filaments
galaxy halos
dark matter
star clusters
gas cloud
Avogadro constant
Smoothed Particle Hydrodynamics
Dark matter
Boltzmann equation
Poisson's Equation
Friedmann equations
perturbation theory
Solar System

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