We argue validity of purely ghost kinetic operator in open string field
theory from the perspective of the modern analytic method based on the KBc
subalgebra. A purely ghost kinetic operator is obtained as a result of gauge
fixing string field theory around the identity based tachyon vacuum solution.
It is shown that the obtained kinetic operator is not equivalent to the
midpoint insertion of the conformal ghost which is extensively studied in
literature. We also find that the equation of motion does not allow any
nontrivial solutions.Comment: 6 pages, Section 2 is added for publicatio