English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Aims. We investigated the gravitational effects of a scalar field withinscalar-tensor gravity as an alternative to dark matter. Motivated by chameleon,symmetron and f(R)-gravity models, we studied a phenomenological scenario wherethe scalar field has both a mass (i.e. interaction length) and a couplingconstant to the ordinary matter which scale with the local properties of theconsidered astrophysical system. Methods. We analysed the feasibility of thisscenario using the modified gravitational potential obtained in its context andapplied it to the galactic and hot gas/stellar dynamics in galaxy clusters andelliptical/spiral galaxies respectively. This is intended to be a first step inassessing the viability of this new approach in the context of "alternativegravity" models. Results. The main results are: 1. the velocity dispersion ofelliptical galaxies can be fitted remarkably well by the suggested scalarfield, with model significance similar to a classical Navarro-Frenk-White darkhalo profile; 2. the analysis of the stellar dynamics and the gas equilibriumin elliptical galaxies has shown that the scalar field can couple with ordinarymatter with different strengths (different coupling constants) producing and/ordepending on the different clustering state of matter components; 3. ellipticaland spiral galaxies, combined with clusters of galaxies, show evidentcorrelations among theory parameters which suggest the general validity of ourresults at all scales and a way toward a possible unification of the theory forall types of gravitational systems we considered. All these results demonstratethat the proposed scalar field scenario can work fairly well as an alternativeto dark matter.

Unifying static analysis of gravitational structures with a scale-dependent scalar field gravity as an alternative to dark matter