Constraints on the tensor mode from large scale structure observations

Observational data on the large scale structure (LSS) of the Universe are used to establish an upper limit for the amplitude of the tensor mode marginalized over all other cosmological parameters within the class of adiabatic inflationary models. It is shown that the upper 1$\sigma$ limit for the contribution of a tensor mode to the COBE DMR data is T/S$<1$.