MOTION OF A HEAVY PARTICLE IN AN INFINITE ONE DIMENSIONAL GAS OF HARD SPHERES
MOTION OF A HEAVY PARTICLE IN AN INFINITE ONE DIMENSIONAL GAS OF HARD SPHERES
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DOI:
10.1007/bf00536757
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发表时间:
1971-01-01
期刊:
影响因子:
--
通讯作者:
HOLLEY, R
中科院分区:
文献类型:
--
作者:
HOLLEY, R
In this paper we find a probabilistic model for the motion of a large heavy particle colliding with many light particles. The physical situation is as follows. Consider a one dimensional world in which there are countably many particles distributed at random and each is moving independently of the others except for collisions. In our model the particles will move with constant velocity until they collide with other particles. We will assume that all collisions are perfectly elastic, conserving momentum and energy; and therefore, when two particles with the same mass collide, they simply exchange velocities. Now the problem that we will be concerned with is to describe the behavior of a particle which is much heavier than the others.Before beginning on this problem consider a system as described above in which particles of equal mass are started at all of the even integers and each is independently given a velocity ___ 1 with probability 89 We will consider the one which started at zero as a distinguished particle. It is clear that if we observe this particle after every unit time, it will be performing a simple random walk. However, more than this is true. If we denote by X (t) the position of our distinguished particle at time t, the following theorem is true.(See Billingsley [1] p. 68 for the proof.)