Observational cosmology
2021; Oxford University Press; Linguagem: Inglês
10.1093/oso/9780192895646.003.0025
Autores Tópico(s)Cosmology and Gravitation Theories
ResumoAbstract The main strands of observation in cosmology are presented. These are redshift surveys using standard candles; galaxy distributions; age estimates drawing on a number of strands of evidence; and the CMB radiation. The chapter begins with a discussion of systemtic and statistical error in measurements, and explains the terminology of “Lambda CDM” model. Observations are combined with the Friedman equation in order to constrain the density parameters in a LCDM model. Data from supernova surveys are used to obtain the Hubble parameter and the deceleration parameter, and hence evidence of an accelerating expansion. Evidence of the BAO process is deduced from sky surveys, and used to constrain the spatial curvature. The CMB radiation is discussed at length. The Sachs-Wolfe effect is obtained by a simple calculation,. The method to deduce spatial curvature from the position of the acoustic peaks is outlined. Further features such as spectal index and polarization are briefly discussed.
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