We compute the shear modulus of structural glasses from a first principle
approach based on the cloned liquid theory. We find that the intra-state
shear-modulus, which corresponds to the plateau modulus measured in linear
visco-elastic measurements, strongly depends on temperature and vanishes
continuously when the temperature is increased beyond the glass temperature.Comment: 5 pages, 2 figures. Revised version. An error in Fig 2 due to an
error in the plotting program is corrected. The revised figure is submitted
to PRL as an erratu
