  This work presents a homogeneous determination of lithium abundances in a
large sample of giant-planet hosting stars (N=117), and a control sample of
disk stars without detected planets (N=145). The lithium abundances were
derived using a detailed profile fitting of the Li I doublet at lambda 6708 A
in LTE. The planet hosting and comparison stars were chosen to have significant
overlap in their respective physical properties, including effective
temperatures, luminosities, masses, metallicities and ages. The combination of
uniform data and homogeneous analysis with well selected samples, makes this
study well-suited to probe for possible differences in the lithium abundances
found in planet hosting stars. An overall comparison between the two samples
reveals no obvious differences between stars with and without planets. Closer
examination of the behavior of the Li abundances over a narrow range of
effective temperature (5700 K < Teff < 5850 K) indicates subtle differences
between the two stellar samples; this temperature range is particularly
sensitive to various physical processes that can deplete lithium. In this Teff
range planet hosting stars have lower Li abundances (by ~0.26 dex on average)
than the comparison stars, although this segregation may be influenced by
combining stars from a range of ages, metallicities and masses. When stars with
very restricted ranges in metallicity ([Fe/H] = 0.00 to +0.20 dex) and mass (M
~ 1.05 - 1.15 Msun are compared, however, both stars with and without planets
exhibit similar behaviors in the lithium abundance with stellar age, suggesting
that there are no differences in the lithium abundances between stars with
planets and stars not known to have planets.
