Safety in numbers: Gravitational Lensing Degradation of the Luminosity Distance-Redshift Relation

摘要: Observation of the expansion history universe allows exploration physical properties and energy density universe's various constituents. Standardizable candles such as Type Ia supernovae remain one most promising robust tools in this endeavor by allowing for a direct measure luminosity distance-redshift curve thereby producing detailed studies dark responsible currently accelerating expansion. As observations are pushed to higher redshifts, observed flux is increasingly affected gravitational lensing magnification due intervening structure along line sight. We simulate analyze non-Gaussian probability distribution function deamplification amplification standard candles, quantify effect convolution over many independent sources (which acts restore intrinsic average [unlensed] conservation), compute additional uncertainty on derived cosmological parameters. find that, case large numbers sources, any particular sight can be approximated Gaussian with deviation given σeff = 0.088z redshift z. The resulting "degradation factor" factor 3 reduction effective number usable at z 1.5 (for dispersion 10%).