  The B-twisted topological sigma model coupled to topological gravity is
supposed to be described by an ordinary field theory: a type of holomorphic
Chern-Simons theory for the open string, and the Kodaira-Spencer theory for the
closed string. We show that the B model can be represented as a PARTICLE
theory, obtained by reducing the sigma model to one dimension, and replacing
the coupling to topological gravity by a coupling to a twisted one-dimensional
supergravity. The particle can be defined on ANY Kahler manifold--it does not
require the Calabi-Yau condition--so it may provide a more generalized setting
for the B model than the topological sigma model. The one-loop partition
function of the particle can be written in terms of the Ray-Singer torsion of
the manifold, and agrees with that of the original B model. After showing how
to deform the Kahler and complex structures in the particle, we prove the
independence of this partition function on the Kahler structure, and
investigate the origin of the holomorphic anomaly. To define other amplitudes,
one needs to introduce interactions into the particle. The particle will then
define a field theory, which may or may not be the Chern-Simons or
Kodaira-Spencer theories.
