We present an analysis of the unusual optical light curve of the gamma-ray
burst GRB~081029, which occurred at a redshift of z = 3.8479$. We combine X-ray
and optical observations from the Swift X-Ray Telescope and the Swift
UltraViolet/Optical Telescope with optical and infrared data obtained using the
REM and ROTSE telescopes to construct a detailed data set extending from 86 s
to approximately 100,000 s after the BAT trigger. Our data also cover a wide
energy range, from 10 keV to 0.77 eV (1.24 Angstrom to 16,000 Angstrom). The
X-ray afterglow shows a shallow initial decay followed by a rapid decay
starting at about 18,000s. The optical and infrared afterglow, however, shows
an uncharacteristic rise at about 5000 s that does not correspond to any
feature in the X-ray light curve. Our data are not consistent with synchrotron
radiation from a single-component jet interacting with an external medium. We
do, however, find that the observed light curve can be explained using
multi-component model for the jet.Comment: 4 pages, 3 figures, to appear in the AIP Conference Proceedings for
the Gamma-Ray Burst 2010 Conference, Annapolis, MD, USA, November 201