We expect a detectable correlation between two seemingly unrelated quantities: the four-point function of the cosmic microwave background (CMB) and the amplitude of flux decrements in quasar (QSO) spectra. The amplitude of CMB convergence in a given direction measures the projected surface density of matter. Measurements of QSO flux decrements trace the small-scale distribution of gas along a given line of sight. While the cross-correlation between these two measurements is small for a single line of sight, upcoming large surveys should enable its detection. This paper presents analytical estimates for the signal-to-noise ratio (S/N) for measurements of the cross-correlation between the flux decrement and the convergence, <delta F kappa >, and for measurements of the cross-correlation between the variance in flux decrement and the convergence, <(delta F)(2)kappa >. For the ongoing BOSS (SDSS-III) and Planck surveys, we estimate an S/N of 30 and 9.6 for these two correlations. For the proposed BigBOSS and ACTPOL surveys, we estimate an S/N of 130 and 50, respectively. Since <(delta F)(2)kappa > proportional to sigma(4)(8), the amplitude of these cross-correlations can potentially be used to measure the amplitude of sigma(8) at z similar to 2%-2.5% with BOSS and Planck and even better with future data sets. These measurements have the potential to test alternative theories for dark energy and to constrain the mass of the neutrino. The large potential signal estimated in our analytical calculations motivates tests with nonlinear hydrodynamic simulations and analyses of upcoming data sets.

Cross-correlations of the Lyα forest with weak-lensing convergence. analytical estimates of signal-to-noise ratio and implications for neutrino mass and dark energy / Vallinotto, A.; Viel, Matteo; Das, S.; Spergel, D. N.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 735:1(2011), pp. 1-20. [10.1088/0004-637X/735/1/38]

Cross-correlations of the Lyα forest with weak-lensing convergence. analytical estimates of signal-to-noise ratio and implications for neutrino mass and dark energy

Viel, Matteo;
2011-01-01

Abstract

We expect a detectable correlation between two seemingly unrelated quantities: the four-point function of the cosmic microwave background (CMB) and the amplitude of flux decrements in quasar (QSO) spectra. The amplitude of CMB convergence in a given direction measures the projected surface density of matter. Measurements of QSO flux decrements trace the small-scale distribution of gas along a given line of sight. While the cross-correlation between these two measurements is small for a single line of sight, upcoming large surveys should enable its detection. This paper presents analytical estimates for the signal-to-noise ratio (S/N) for measurements of the cross-correlation between the flux decrement and the convergence, , and for measurements of the cross-correlation between the variance in flux decrement and the convergence, <(delta F)(2)kappa >. For the ongoing BOSS (SDSS-III) and Planck surveys, we estimate an S/N of 30 and 9.6 for these two correlations. For the proposed BigBOSS and ACTPOL surveys, we estimate an S/N of 130 and 50, respectively. Since <(delta F)(2)kappa > proportional to sigma(4)(8), the amplitude of these cross-correlations can potentially be used to measure the amplitude of sigma(8) at z similar to 2%-2.5% with BOSS and Planck and even better with future data sets. These measurements have the potential to test alternative theories for dark energy and to constrain the mass of the neutrino. The large potential signal estimated in our analytical calculations motivates tests with nonlinear hydrodynamic simulations and analyses of upcoming data sets.
2011
735
1
1
20
38
Vallinotto, A.; Viel, Matteo; Das, S.; Spergel, D. N.
File in questo prodotto:
File Dimensione Formato  
Vallinotto_2011_ApJ_735_38.pdf

accesso aperto

Tipologia: Versione Editoriale (PDF)
Licenza: Non specificato
Dimensione 1.74 MB
Formato Adobe PDF
1.74 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/17276
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 6
social impact