Flat spacetime vacuum in loop quantum gravity

We propose a state in loop quantum gravity theory with zero cosmological constant such that it could be associated with the flat spacetime vacuum solution. This state is constructed by defining the loop transform coefficients of a flat connection wavefunction in the holomorphic representation which satisfies all the constraints of quantum general relativity and it is peaked around the flat space triads. The loop transform coefficients are defined as spin-foam state sum invariants of the spin networks embedded in the spatial manifold for the SU(2) quantum group. We also obtain an expression for the vacuum wavefunction in the triad representation, by defining the corresponding spin network functional integrals as SU(2) quantum group state sums.