Observational constraints on running vacuum model

Abstract

We investigate the power spectra of the CMB temperature and matter density in the running vacuum model (RVM) with the time-dependent cosmological constant of Λ = 3νH 2 + Λ 0 , where H is the Hubble parameter. In this model, dark energy decreases in time and decays to both matter and radiation. By using the Markov chain Monte Carlo method, we constrain the model parameter ν as well as the cosmological observables. Explicitly, we obtain ν ≤ 1.54 × 10 −4 (68% confidence level) in the RVM with the best-fit χ 2 RVM = 13968.8, which is slightly smaller than χ 2 ΛCDM = 13969.8 in the ΛCDM model of ν = 0. * Electronic address:

Running vacuum model in non-flat universe

“…in the non-flat universe of RVM for the data set of CMB+BAO+SN+WL+f σ 8 , which is similar to the previous result of 1.54 × 10 −4 at 68 % C.L. in RVM for the flat universe[31]. For the density parameter of curvature, |Ω K |, we find that it is constrained to be ≤ O(10 −2 ) in both RVM and ΛCDM.…”

“…To see this effect, we compare CMB power spectra of RVM and ΛCDM with different ν and Ω K along with the observational data from Planck 2018 [40]. From the previous studies in the literature [16,31,32] with 0 ≤ ν ≤ O(10 −3 ) in RVM for the flat universe and the result of −0.007 ≥ Ω K ≥ −0.095 at 99 % C.L. in Ref.…”

“…The running vacuum model (RVM) [13,14] has been introduced in order to solve the "coincidence problem", where the cosmological constant term is assumed to be varying with the Hubble parameter H. This model links the existence of dark energy to the theoretical mechanism of the quantum field, which may trigger the primordial inflation scenario [15], and fit with the observational data better than ΛCDM [16]. In the literature, the spatially flat RVM has been extensively investigated [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”

Constraints on power law cosmology from cosmic chronometer, standard ruler, and standard candle data

“…There is now a broad consensus that the ΛCDM model is sufficient to describe the dynamics of the Universe, on large scales, throughout most of its history [1]. Some groups [2][3][4][5][6][7][8][9][10][11][12][13][14][15] have found evidence of small departures from the ΛCDM model (such as dynamical dark energy or large-scale spatial curvature), but these findings have generally not risen to the level of significance necessary to dethrone ΛCDM from its position as the standard model of cosmology. More radical alternatives to the standard model are conceivable, however.…”

First study of reionization in tilted flat and untilted non-flat dynamical dark energy inflation models

“…1 There are a number 1 For discussions of the φCDM model see Samushia et al (2007), of recent suggestions that spatially-flat dynamical dark energy models better fit current observational data than does the standard spatially-flat ΛCDM model (see, e.g. Zhang et al 2017;Ooba et al 2018a;Park & Ratra 2018a;Wang et al 2018;Park & Ratra 2018c;Sola et al 2018;Zhang et al 2019). We also use reionization observations to constrain spatial curvature.…”