JSM Preliminary Online Program
This is the preliminary program for the 2007 Joint Statistical Meetings in Salt Lake City, Utah.

The views expressed here are those of the individual authors
and not necessarily those of the ASA or its board, officers, or staff.

Back to main JSM 2007 Program page

Activity Number: 367
Type: Topic Contributed
Date/Time: Wednesday, August 1, 2007 : 8:30 AM to 10:20 AM
Sponsor: Section on Bayesian Statistical Science
Abstract - #309548
Title: An Exploratory Statistical Study of the Measured Motion of the Guide Star Used in a New Test of Einstein's Universe
Author(s): Jingchen Liu*+ and Xiao-li Meng and Michael Ratner and Irwin Shapiro
Companies: Harvard University and Harvard University and Harvard-Smithsonian Center for Astrophysics and Harvard-Smithsonian Center for Astrophysics
Address: 1 Oxford Street, Cambridge, MA, 02138,

General relativity predicts that the phenomenon of "frame-dragging" slowly alters the direction of spin of Earth-orbiting gyroscopes. NASA's Gravity Probe B satellite measured the orientation of such freely falling gyroscopes with respect to a guide star. This star's motion with respect to "fixed points" in the distant universe thus needed to be measured independently. VLBI measurements spread over 14 years yielded 39 positions of this radio-emitting guide star. We use Bayesian methods and a linear regression model of the star's motion to study the effects of various assumptions involving the parameters of both the physical model and the measurement noise model. We find that a wide range of different assumptions lead to a narrow range of point estimates and error distributions.

  • The address information is for the authors that have a + after their name.
  • Authors who are presenting talks have a * after their name.

Back to the full JSM 2007 program

JSM 2007 For information, contact jsm@amstat.org or phone (888) 231-3473. If you have questions about the Continuing Education program, please contact the Education Department.
Revised September, 2007