Fingerprinting dark energy

• Verfasst von: Sapone, Domenico [VerfasserIn]
• Verfasst von: Kunz, Martin [VerfasserIn]
• Verfasst von: Amendola, Luca [VerfasserIn]
• Titel: Fingerprinting dark energy
• Titelzusatz: II. Weak lensing and galaxy clustering tests
• Verf.angabe: Domenico Sapone (Departamento de Física Teórica and Instituto de Física Teórica, Universidad Autónoma de Madrid IFT-UAM/CSIC, Cantoblanco, Madrid, Spain), Martin Kunz (Département de Physique Théorique, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genéve 4, Switzerland, Institut d'Astrophysique Spatiale, Université Paris-Sud XI, Orsay 91405, France, and Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH, United Kingdom), Luca Amendola (University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany, and INAF/Rome, Italy)
• E-Jahr: 2010
• Jahr: 30 November 2010
• Umfang: 16 S.
• Fussnoten: Gesehen am 13.11.2017
• Titel Quelle: Enthalten in: Physical review. D, Particles, fields, gravitation, and cosmology
• Ort Quelle: [Erscheinungsort nicht ermittelbar] : Soc., 1970
• Jahr Quelle: 2010
• Band/Heft Quelle: 82(2010), 10, Artikel-ID 103535, Seite 1-16
• ISSN Quelle: 1550-2368
• ISSN Quelle: 1089-4918
• DOI: doi:10.1103/PhysRevD.82.103535
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1565270231

Abstract

The characterization of dark energy is a central task of cosmology. To go beyond a cosmological constant, we need to introduce at least an equation of state and a sound speed and consider observational tests that involve perturbations. If dark energy is not completely homogeneous on observable scales, then the Poisson equation is modified and dark matter clustering is directly affected. One can then search for observational effects of dark energy clustering using dark matter as a probe. In this paper we exploit an analytical approximate solution of the perturbation equations in a general dark energy cosmology to analyze the performance of next-decade large-scale surveys in constraining equation of state and sound speed. We find that tomographic weak lensing and galaxy redshift surveys can constrain the sound speed of the dark energy only if the latter is small, of the order of cs≲0.01 (in units of c). For larger sound speeds the error grows to 100% and more. We conclude that large-scale structure observations contain very little information about the perturbations in canonical scalar field models with a sound speed of unity. Nevertheless, they are able to detect the presence of cold dark energy, i.e. a dark energy with nonrelativistic speed of sound.