Delfino, GesualdoNiccoli, Giuliano2006-04-122011-09-072006-04-122011-09-072006-04-12JHEP 0605 (2006) 035https://openscience.sissa.it/handle/1963/1813The composite operator T\bar{T}, obtained from the components of the energy-momentum tensor, enjoys a quite general characterization in two-dimensional quantum field theory also away from criticality. We use the form factor bootstrap supplemented by asymptotic conditions to determine its matrix elements in the sinh-Gordon model. The results extend to the breather sector of the sine-Gordon model and to the minimal models M_{2/(2N+3)} perturbed by the operator phi_{1,3}.350222 bytesapplication/pdfen-USPreprint