126 Parabolic Orbits of Meteor Streams

Meteor Streams and Parent Bodies

Problem of meteor orbit determination for a given parent body is discussed. Some of the published methods for obtaining meteoroid’s orbital elements at the moment of intersecting Earth’s orbit on the basis of geometrical variation of parent body’s orbital elements are discussed. The main result concerns the following two facts: i) in real situations physical quantities for the change of orbital...

Fitting orbits to tidal streams

Recent years have seen the discovery of many tidal streams through the Galaxy. Relatively straightforward observations of a stream allow one to deduce three phase-space coordinates of an orbit. An algorithm is presented that reconstructs the missing phasespace coordinates from these data. The reconstruction starts from assumed values of the Galactic potential and a distance to one point on the ...

Coadjoint Orbits of Siegel Parabolic Subgroups

Let P+(n) be the Siegel parabolic subgroup of O(n, n), and P−(n) be the Siegel parabolic subgroup of Sp2n(R). In this paper, we study the coadjoint orbits of P±(n). We establish a one-to-one correspondence between the real coadjoint orbits of Sp2n(R) and the principal coadjoint orbits of P+(2n), and a one-to-one correspondence between the real coadjoint orbits of O(p, n− p) with p ∈ [0, n] and ...

Heteroclinic orbits of semilinear parabolic equations

Nilpotent Orbits and Theta-stable Parabolic Subalgebras

In this work, we present a new classification of nilpotent orbits in a real reductive Lie algebra g under the action of its adjoint group. Our classification generalizes the Bala-Carter classification of the nilpotent orbits of complex semisimple Lie algebras. Our theory takes full advantage of the work of Kostant and Rallis on pC , the “complex symmetric space associated with g”. The Kostant-S...