eng Science and Education Publishing Frontiers of Astronomy Astrophysics and Cosmology 2018-12-04 4 1 30 31 10.12691/faac-4-1-3 FAAC2018413 article Shi-Hao Chen shchen@nenu.edu.cn 1 Institute of Theoretical Physics, Northeast Normal University, Changchun, China Based on a model of the universe without singularity, it is proven that the energy density of the vacuum state must be zero or a finite and small positive number. Consequently, the effective cosmological constant is easily determined according to the observations. http://pubs.sciepub.com/faac/4/1/3/faac-4-1-3.pdf cosmological constant the energy density of the vacuum state symmetry breaking gravitational mass