Time-dependent cosmological constant in the Jackiw-Teitelboim cosmology M. Alves, J. Barcelos-Neto, M. Novello and J. M. Salim Europhys. Lett., 61 5 (2003) 715-720 Published online: 01 February 2003 DOI: 10.1209/epl/i2003-00100-3