Let H be a closed, noncompact subgroup of a simple Lie group G, such that G/H admits an invariant Lorentz metric. We show that if G = SO(2, n), with n ≥ 3, then the identity component H of H is conjugate to SO(1, n). Also, if G = SO(1, n), with n ≥ 3, then H is conjugate to SO(1, n− 1).

We present a classification, up to isomorphisms, of all the homogeneous spaces of the Lorentz group with dimension lower than six. At the same time, we classify, up to conjugation, all the non-discrete closed subgroup of the Lorentz group and all the subalgebras of the Lorentz Lie algebra. We also study the covariant mappings between some pairs of homogeneous spaces. This exercise is done witho...

When working with groups of robots it may be very difficult to determine what characteristics the group requires in order to perform a task most efficiently-i.e., in the least time. Some researchers have used groups of behaviorally differentiated robots-where the robots do not perform the same actions-and others have used behaviorally homogeneous groups. None of this research, however, explicit...

Large scale coordination without dominant, consistent leadership is frequent in nature. How individuals emerge from within the group as leaders, however transitory this position may be, has become an increasingly common question asked. This question is further complicated by the fact that in many of these aggregations, differences between individuals are minor and the group is largely considere...