Bayesian analysis for rotational curves with ℓ-boson stars as a dark matter component

Abstract

Using Low Brightness Surface Galaxies (LBSG) rotational curves we inferred the free parameters of ℓ-boson stars as a dark matter component. The ℓ-boson stars are numerical solutions to the non-relativistic limit of the Einstein-Klein-Gordon system, the Schrödinger-Poisson (SP) system. These solutions are parametrized by an angular momentum number ℓ = (N - 1)/2 and an excitation number n. We perform a bayesian analysis by modifying the SimpleMC code to perform the parameter inference, for the cases with ℓ = 0, ℓ = 1 and multi-states of ℓ-boson stars. We used the Akaike information criterion (AIC), Bayesian information criterion and the Bayes factor to compare the excited state (ℓ=1) and the multi-state case with the ground state (ℓ=0) as the base model due to its simplicity. We found that the data in most galaxies in the sample favours the multi-states case and that the scalar field mass tends to be slightly bigger than the ground state case.

Boson star superradiance

“…[16,17] for a review. Furthermore, boson stars can serve as dark matter sources [18][19][20][21][22][23] and black hole mimickers [24][25][26][27]. They and their binary systems can emit distinctive gravitational radiation potentially detectable by future gravitational wave experiments [28][29][30][31][32][33][34][35][36][37][38][39].…”

Model-independent reconstruction of the interacting dark energy kernel: Binned and Gaussian process

“…In order to explain the small scale structure formation, or at least to ameliorate the problems associated with the CDM model, several alternatives have been introduced. One viable option is to replace the standard CDM with Scalar Field dark matter components [30][31][32][33][34][35] or by introducing the Self Interacting dark matter [36][37][38], or to support the warm dark matter scenario [39,40]. Regarding the current accelerated expansion of the Universe, a natural extension to the constant EoS is introducing phenomenological dynamics to model the general behavior of the DE, whose main methodology relies on giving a functional form with a dependence on redshift/scale factor, i.e., w DE = w(z), see, e.g., [41][42][43][44][45].…”