Particle Production in Ekpyrotic Scenarios
  We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction is sufficient to lead to a hot state of matter after the bounce. Hence, no separate reheating mechanism is necessary. 
W. S. Hipolito-Ricaldi, Robert Brandenberger, Elisa G.M. Ferreira, L.   L. Graef
hep-th astro-ph.CO gr-qc hep-ph