We study the dynamics of critical collapse of a spherically symmetric scalar
field. Approximate analytic expressions for the metric functions and matter
field in the large-radius region are obtained. It is found that because of the
boundary conditions at the center, in the central region, the equation of
motion for the scalar field is reduced to the flat-spacetime form. On the other
hand, due to the connection to its neighbouring region where gravity plays an
important role, the scalar field in the central region feels the gravitational
effects indirectly.Comment: 6 pages, 5 figure