%0 Journal Article %T On the theory of Double Quantum NMR in polymer systems: the second cumulant approximation for many spin I=1/2 systems %A N. Fatkullin %A C. Mattea %A S. Stapf %J Physics %D 2013 %I arXiv %R 10.1063/1.4830410 %X General analytical expressions for Double Quantum Nuclear Magnetic Resonance (NMR) kinetic curves of many-spin I=1/2 systems are derived with an accuracy of the second cumulant approximation. The expressions obtained exactly describe the initial part of the kinetic curves and provide a reasonable approximation up to times of about twice the effective spin-relaxation time. For the case when the system contains two isolated spins, this result exactly reproduces known expressions. In the case of polymer melts, the intermolecular magnetic dipole-dipole interactions significantly influence the time dependence of the DQ NMR kinetic curves. %U http://arxiv.org/abs/1309.5188v1