The topology of the intergalactic medium from multiple lines of sight to quasars

The spatial distribution of the gas in the intergalactic medium and its physical properties can be recovered thanks to the characteristics of the Lyα absorption lines that are observed in the spectra of high redshift quasars, the so-called Lyα forest. We use inversion methods applied to a network of lines of sight to infer the topology of the intergalactic medium, based on reconstruction of the density field. The method has already been tested on simulated data.