  The impact of the QCD critical point on the propagation of nonlinear waves
has been studied. The effects have been investigated within the scope of
second-order causal dissipative hydrodynamics by incorporating the critical
point into the equation of state, and the scaling behaviour of transport
coefficients and of thermodynamic response functions. Near the critical point,
the nonlinear waves are found to be significantly damped which may result in
the disappearance of the Mach cone effects of the away side jet. Such damping
may lead to enhancement in the fluctuations of elliptic and higher flow
coefficients. Therefore, the disappearance of Mach cone effects and the
enhancement of fluctuations in flow harmonics in the event-by-event analysis
may be considered as signals of the critical endpoint.
