Only one hotel is at walking distance from the conference place (now fully booked). You may also choose a hotel in Paris (it takes about 35 mn RER + 15 mn walk within the campus to come to the conference place from Paris - e.g. from Luxembourg RER station), or in the nearby towns (from Gif-sur-Yvette, only 5mn RER). From Paris or from Gif-sur-Yvette, there is a RER at least every 15 mn.
Hotel lists

In the hotel lists below, phone numbers are given for a call from France (01 ....). For calls from abroad, you should replace 01 by 33-1.