Chaplygin gas may prevent big trip
  This paper deals with the study of the accretion of a generalized Chaplygin gas with equation of state $p=-A/\rho^\alpha$ onto wormholes. We have obtained that when dominant energy condition is violated the size of wormhole increases with the scale factor up to a given plateau. On the regime where the dominant energy condition is satisfied our model predicts a steady decreasing of the wormhole size as generalized Chaplygin gas is accreted. Our main conclusion is that the big trip mechanism is prevented in a large region of the physical parameters of the used model. 
Jos\'e A. Jim\'enez Madrid (IAA, Granada & IMAFF, Madrid)