J2 effect and the collision restricted three–body problem

The existence of a new class of inclined periodic orbits of the collision restricted three–body problem is shown. The symmetric periodic solutions found are perturbations of elliptic kepler orbits and they exist only for special values of the inclination and are related to the motion of a satellite around an oblate planet

Indicadores contables para medir el riesgo. Utilidad de la información contable en el mercado español

El objetivo de este trabajo es analizar qué información contable permite medir el riesgo de las empresas que forman parte del Mercado de Capitales Español. Analizamos la información contable publicada por 73 empresas españolas, que cotizaban en el Mercado de Capitales Español durante el período 1992-2002, a través de siete indicadores. Estudiamos la conexión entre la información contable y la beta de las acciones, que es la medida de riesgo que proporciona el mercado de capitales. Analizamos la influencia que puede tener en el nivel de utilidad de la información contable, como medida del riesgo, el hecho de que la beta se determine utilizando el IBEX-35 o el IGBM (Índice General de la Bolsa de Madrid). Los resultados obtenidos muestran que solo utilizando el IBEX-35 existe cierta conexión entre la información contable y el riesgo de mercado, y que solo el endeudamiento y el ratio payout explican de forma significativa dicho riesgo

Highly eccentric hip-hop solutions of the 2N-body problem

We show the existence of families of hip-hop solutions in the equal-mass 2N-body problem which are close to highly eccentric planar elliptic homographic motions of 2N bodies plus small perpendicular non-harmonic oscillations. By introducing a parameter Є, the homographic motion and the small amplitude oscillations can be uncoupled into a purely Keplerian homographic motion of fixed period and a vertical oscillation described by a Hill type equation. Small changes in the eccentricity induce large variations in the period of the perpendicular oscillation and give rise, via a Bolzano argument, to resonant periodic solutions of the uncoupled system in a rotating frame. For small Є ≠ 0, the topological transversality persists and Brouwer's fixed point theorem shows the existence of this kind of solutions in the full system.Postprint (author’s final draft

Hip-hop solutions of the 2N-body problem

Hip–Hop solutions of the 2N–body problem with equal masses are shown to exist using an analytic continuation argument. These solutions are close to planar regular 2N–gon relative equilibria with small vertical oscillations. For fixed N, an infinity of these solutions are three–imensional choreographies, with all the in the inertial frame.Peer ReviewedPostprint (author’s final draft

J2 effect and elliptic inclined periodic orbits in the collision three-body problem

The existence of a new class of inclined periodic orbits of the collision restricted three{body problem is shown. The symmetric periodic solutions found are perturbations of elliptic kepler orbits and they exist only for special values of the inclination and are related to the motion of a satellite around an oblate planet.Peer Reviewe

Hip-hop solutions of the 2N-body problem

Hip–Hop solutions of the 2N–body problem with equal masses are shown to exist using an analytic continuation argument. These solutions are close to planar regular 2N–gon relative equilibria with small vertical oscillations. For fixed N, an infinity of these solutions are three–imensional choreographies, with all the in the inertial frame.Peer Reviewe

Highly eccentric hip-hop solutions of the 2N-body problem

We show the existence of families of hip-hop solutions in the equal-mass 2N-body problem which are close to highly eccentric planar elliptic homographic motions of 2N bodies plus small perpendicular non-harmonic oscillations. By introducing a parameter Є, the homographic motion and the small amplitude oscillations can be uncoupled into a purely Keplerian homographic motion of fixed period and a vertical oscillation described by a Hill type equation. Small changes in the eccentricity induce large variations in the period of the perpendicular oscillation and give rise, via a Bolzano argument, to resonant periodic solutions of the uncoupled system in a rotating frame. For small Є ≠ 0, the topological transversality persists and Brouwer's fixed point theorem shows the existence of this kind of solutions in the full system