Carregant...
Fitxers
Tipus de document
ArticleVersió
Versió acceptadaData de publicació
Tots els drets reservats
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/127543
The bispectrum of f(R) cosmologies
Títol de la revista
Director/Tutor
ISSN de la revista
Títol del volum
Recurs relacionat
Resum
In this paper we analyze a suite of cosmological simulations of modified gravitational action f(R) models, where cosmic acceleration is induced by a scalar field that acts as a fifth force on all forms of matter. In particular, we focus on the bispectrum of the dark matter density field on mildly non-linear scales. For models with the same initial power spectrum, the dark matter bispectrum shows significant differences for cases where the final dark matter power spectrum also differs. Given the different dependence on bias of the galaxy power spectrum and bispectrum, bispectrum measurements can close the loophole of galaxy bias hiding differences in the power spectrum. Alternatively, changes in the initial power spectrum can also hide differences. By constructing ΛCDM models with very similar final non-linear power spectra, we show that the differences in the bispectrum are reduced (lesssim4%) and are comparable with differences in the imperfectly matched power spectra. These results indicate that the bispectrum depends mainly on the power spectrum and less sensitively on the gravitational signatures of the f(R) model. This weak dependence of the matter bispectrum on gravity makes it useful for breaking degeneracies associated with galaxy bias, even for models beyond general relativity.
Matèries
Matèries (anglès)
Citació
Citació
GIL MARÍN, Héctor, SCHMIDT, Fabian, HU, Wayne, JIMÉNEZ, Raúl (jiménez tellado), VERDE, Licia. The bispectrum of f(R) cosmologies. _Journal of Cosmology and Astroparticle Physics_. 2011. Vol. 2011, núm. 019. [consulta: 20 de gener de 2026]. ISSN: 1475-7516. [Disponible a: https://hdl.handle.net/2445/127543]