  Forward-backward asymmetries $A_{FB}^t$ and $A_{FB}^\ell$ are observed in the
top quark $t$ rapidity distribution and in the rapidity distribution of charged
leptons $\ell$ from top quark decay at the Tevatron proton-antiproton collider,
and a charge asymmetry $A_C$ is seen in proton-proton collisions at the Large
Hadron Collider (LHC). In this presentation, I summarize research my
collaborators and I have done on the interpretation and implications of the
Tevatron asymmetries and provide expectations for $A_C$ at the LHC. The two
asymmetries $A_{FB}^t$ and $A_{FB}^\ell$ are connected through the $(V-A)$ spin
correlation between the charged lepton and the top quark with different
polarization states. The ratio of the two asymmetries provides independent
insight into the physics interpretation of the top quark asymmetry. A new
physics model which produces more right-handed than left-handed top quarks
appears to be indicated by the present Tevatron data, but an improvement in
precision is desirable.
