  We introduce a framework for model reduction of chain models for dissipative
particle dynamics (DPD) simulations, where the characteristic size of the
chain, pressure, density, and temperature are preserved. The proposed
methodology reduces the number of degrees of freedom required to represent a
particular system with complex molecules (e.g., linear polymers). Based on
geometrical considerations we map fine-grained models to a reference state
through a consistent scaling of the system, where short length and fast time
scales are disregarded while the properties governing the phase equilibria are
preserved. Following this coarse graining process we consistently represent
high molecular weight DPD chains (i.e., >200 beads per chain) with a
significant reduction in the number of particles required (i.e., > 20 times the
original system).
