Gamma Ray Bursts as cosmological tools
  The use of Gamma Ray Bursts as ``standard candles'' has been made possible by the recent discovery of a very tight correlation between their rest frame intrinsic properties. This correlation relates the GRB prompt emission peak spectral energy E_peak to the energy E_gamma corrected for the collimation angle theta_jet of these sources. The possibility to use GRBs to constrain the cosmological parameters and to study the nature of Dark Energy are very promising. 
G. Ghirlanda (1), G. Ghisellini (1), L. Nava (1,2), C. Firmani (1,3)   ((1)Osservatorio Astronomico di Brera, (2)Universita ...