Electronic Journal of Differential Equations, Vol. 2021 (2021), No. 101, pp. 1-23. Title: Global well-posedness for Klein-Gordon-Hartree and fractional Hartree equations on modulation spaces Author: Divyang G. Bhimani (Indian Inst. of Science Education and Research, Pune, India) Abstract: We study the Cauchy problems for the Klein-Gordon (HNLKG), wave (HNLW), and Schrodinger (HNLS) equations with cubic convolution (of Hartree type) nonlinearity. Some global well-posedness and scattering are obtained for the (HNLKG) and (HNLS) with small Cauchy data in some modulation spaces. Global well-posedness for fractional Schrodinger (fNLSH) equation with Hartree type nonlinearity is obtained with Cauchy data in some modulation spaces. Local well-posedness for (HNLW), (fHNLS) and (HNLKG) with rough data in modulation spaces is shown. As a consequence, we get local and global well-posedness and scattering in larger than usual $L^p$-Sobolev spaces. Submitted April 30, 2021. Published December 21, 2021. Math Subject Classifications: 35L71, 35Q55, 42B35, 35A01. Key Words: Klein-Gordon-Hartree equation; fractional Hartree equation; wave-Hartree equation; well-posedness; modulation spaces; small initial data.