In this paper it is shown that several cases of one‐dimensional *N*‐body problems are exactly soluble. The first case describes the motion of three one‐dimensional particles of arbitrary mass which interact with one another via infinite‐strength, repulsive delta‐function potentials. It is found in this case that the stationary‐state solution of the scattering of the three particles is analogous to an electro‐magnetic diffraction problem which has already been solved. The solution to this analogous electro‐magnetic problem is interpreted in terms of particles. Next it is shown that the problem of three particles of equal mass interacting with each other via finite‐ but equal‐strength delta‐function potentials is exactly soluble. This example exhibits rearrangement and bound‐state effects, but no inelastic processes occur. Finally it is shown that the problem of *N* particles of equal mass all interacting with one another via finite‐ but equal‐strength delta functions is exactly soluble. Again no inelastic processes occur, but various types of rearrangements and an *N*‐particle bound state do occur. These rearrangements and the *N*‐particle bound state are illustrated by means of a series of sample calculations.

## REFERENCES

*x*particles is incident from the left and a packet of

*y*particles is incident from the right.

*Methods of Theoretical Physics*(McGraw‐Hill Book Company, Inc., New York, 1953), Vol. II, p. 1644.

*S*matrix it would appear that the condition $s1\u2009=\u2009\u22121,s3\u2009=\u20090,s2\u2009=\u2009\u22121$ is also a state which has no incoming waves. If one applies this condition and looks at the wavefunction, one finds that it does not satisfy the boundary conditions on the delta‐function surfaces. One can construct a wavefunction which does satisfy the boundary conditions on the delta‐function surfaces by a careful limiting process, but this wavefunction increases exponentially at infinity in certain domains.