Constraining Brans-Dicke Gravity with Millisecond Pulsars in Ultracompact Binaries
Abstract
Description
The five accreting, millisecond X-ray pulsars in ultracompact binaries that were recently discovered with the Rossi X-ray Timing Explorer provide excellent candidates for constraining the deviations from general relativity described by the Brans-Dicke parameter omega_BD. I calculate the expected rate of change of the orbital periods of these binaries and discuss the prospects of constraining omega_BD to values that are an order of magnitude larger than current constraints. Finally, I show how measurements of the orbital period derivative in ultracompact binaries can be used to place lower bounds on their orbital inclination.
13 pages, submitted to the Astrophysical Journal
13 pages, submitted to the Astrophysical Journal