Formation of caustics in Dirac-Born-Infeld type scalar field systems
  We investigate the formation of caustics in Dirac-Born-Infeld type scalar
field systems for generic classes of potentials, viz., massive rolling scalar
with potential, $V(\phi)=V_0e^{\pm \frac{1}{2} M^2 \phi^2}$ and inverse
power-law potentials with $V(\phi)=V_0/\phi^n,~0<n<2$. We find that in the case
of\texttt{} exponentially decreasing rolling massive scalar field potential,
there are multi-valued regions and regions of likely to be caustics in the
field configuration. However there are no caustics in the case of exponentially
increasing potential. We show that the formation of caustics is inevitable for
the inverse power-law potentials under consideration in Minkowski space time
whereas caustics do not form in this case in the FRW universe.
