  In this work we study the critical behavior of a three-state opinion model in
the presence of noise. This noise represents the independent behavior, that
plays the role of social temperature. Each agent on a regular D-dimensional
lattice has a probability $q$ to act as independent, i.e., he can choose his
opinion independent of the opinions of his neighbors. Furthermore, with the
complementary probability $1-q$ the agent interacts with a randomly chosen
nearest neighbor through a kinetic exchange. Our numerical results suggest that
the model undergoes nonequilibrium phase transitions at critical points $q_{c}$
that depend on the lattice dimension. These transitions are of order-disorder
type, presenting the same critical exponents of the Ising model. The results
also suggest that the upper critical dimension of the model is $D_{c}=4$, as
for the Ising model. From the social point of view, with increasing number of
social connections, it is easier to observe a majority opinion in the
population.
