2015/10/08 by J. Socorro, M. D'oleire, M. D’oleire +1
Physics and Astronomy · #Ansatz #Barotropic fluid #Black Holes and Theoretical Physics #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Kinetic term #Lagrangian #Pulsars and Gravitational Waves Research #Quintessence #Scalar field #Term (time) #msc:83C15 #physics.gen-ph
paper · pdf · doi:10.1007/s10509-015-2528-8
published as Astrophysics and Space Sci. {\bf 360:20} (2015) · Latex source, 12 pages, 3 figures, accepted in Astrophysics Space Science
arxiv created 2015/10/08 · openalex publication_date 2015/10/20 · openalex created_date 2016/06/24 · arxiv updated 2019/11/21 · openalex updated_date 2026/08/05
We present the case of time-varying cosmological term Λ(t). The main idea arises by proposing that as in the cosmological constant case, the scalar potential is identified as V(ϕ)=2Λ, with Λ a constant, this identification should be kept even when the cosmological term has a temporal dependence, i.e., V(ϕ(t))=2Λ(t). We Use the Lagrangian formalism for a scalar field ϕ with standard kinetic energy and arbitrary potential V(ϕ) and apply this model to the Friedmann-Robertson-Walker (FRW)cosmology. Exact solutions of the field equations are obtained by a special ansatz to solve the Einstein-Klein-Gordon equation and a particular potential for the scalar field and barotropic perfect fluid. We present the evolution on this cosmological term with different scenarios.