R/eZ.R

In CRAC: Cosmology R Analysis Code

#' compute E(z) of given cosmology
#' @description{ Compute the \eqn{E(z)=H(z)/H_0}, or
#'   \deqn{E(z)\equiv\sqrt{\Omega_\mathbf{M}(1+z)^3+\Omega_\mathbf{k}(1+z)^2+
#'   \Omega_\Lambda(1+z)^{(1+w)},}
#'   where we omit the radiation component.
#' }
#' @param z Redshift
#' @param cosmo cosmology parameter list, contains 'omegaM0', 'omegaL0', 'omegaK'
#' @return The dimentionless Hubble constant \eqn{H(z)/H_0}
#' @references Equation (14) in [H99]
#' @seealso \code{\link{eZ2}},\code{\link{parameter.fidcosmo}}
#' 
#' @examples
#' eZ(1.2,parameter.fidcosmo)
eZ <-
function(z, cosmo) {
  sqrt(eZ2(z,cosmo))
}