Guang (Dennis) Yang
Visiting Assistant Professor of Mathematics

 

Web Site

N/A

Contact Information

Office:  227 Malott Hall
Phone:  (607) 254-5058
Fax:  (607) 255-7149
Email:  gy26@cornell.edu

Courses & Office Hours

Education

Ph.D. (2008) Cornell University

Research Area: Dynamical systems, celestial mechanics

My research interests include the analysis of dynamical systems arising from physical problems and the development of analytical and geometric methods that facilitate such analysis. For the past several years, my research activities have revolved around the study of dynamics near resonance. Highlights of the research topics I have worked on are:

  1. Continuation of invariant manifolds. I have developed of a new theory that can continue an invariant manifold and its stable and unstable manifolds (if applicable) under a finite change in their governing system, whereas the traditional theory only considers the persistence of invariant manifolds under small perturbations. When applied to study dynamics near resonance, this new theory is able to establish the existence of weakly normally hyperbolic invariant manifolds and the associated stable and unstable manifolds in resonant regions.
  2. Homoclinic/Heteroclinic Orbits in Resonance. Based on the existence results summarized in the previous topic, I construct and analyze different types of homoclinic/heteroclinic orbits which are transversal intersections of stable and unstable manifolds of invariant manifolds in resonant regions. It includes the application of existing tools, such as the Melnikov method and Exchange Lemma, and the development of new asymptotic methods that can generate higher order approximation of the stable and unstable manifolds under consideration.
  3. Orbital dynamics in a uniformly rotating gravitational field. This physical application serves as a test bed and demonstration of the mathematical results developed in the first two topics. Specifically, it includes the study of the orbital dynamics in resonant regions, where an orbiter's Keplerian mean motion and the rotational rate of the gravitational field are close to a nonzero rational ratio. My goal is to identify 3-dimensional periodic trajectories in a coordinate frame that co-rotates with the gravitational field and then study the dynamics near these periodic trajectories.

Selected Publications

Continuation of invariant manifolds, preprint.

Homoclinic/heteroclinic orbits and chaos in resonance, in progress.

Orbital dynamics in a uniformly rotating second degree and order gravitational field, in progress.


Last modified: January 16, 2008