Multicolour Observations, Inhomogeneity & Evolution

Abstract

We propose a method of testing source evolution theories that is independent of the effects of inhomogeneity, and thus complementary to other studies of evolution. It is suitable for large scale sky surveys, and the new generation of large telescopes. In an earlier paper it was shown that basic cosmological observations - luminosity versus redshift, area distance versus redshift and number counts versus redshift - cannot separate the effects of cosmic inhomogeneity, cosmic evolution and source evolution. We here investigate multicolour observations, and show that by comparing luminosity versus redshift in two or more colours, contraints can be placed on source evolution even if unknown source evolution is present, providing an important test of evolution theories that is complementary to present methods. However, number counts in different colours versus redshift are not useful in separating the effects of source evolution and inhomogeneity.

Latex, 8 pages, using Astronomy & Astrophysics class file "aa.cls". No figures. No tables. Submitted to Astronomy & Astrophysics, 31/10/2000

References in corpus (12)

• The evolution of the galactic morphological types in clusters
• Limitations in using luminosity distance to determine the equation of state of the universe
• A Preliminary Indication of Evolution of Type Ia Supernovae from their Risetimes
• Reconstructing the History of Star Formation in Rich Cluster Cores
• The Fall of the Quasar Population
• Undermining the Cosmological Principle: Almost Isotropic Observations in Inhomogeneous Cosmologies
• Unavoidable Selection Effects in the Analysis of Faint Galaxies in the Hubble Deep Field: Probing the Cosmology and Merger History of Galaxies
• Exploring the evolution of spiral galaxies
• Evolution in the Clustering of Galaxies for Z < 1
• Strong Evolution in the Luminosity-Velocity Relation at z>1?
• Evolution of the probability distribution function of galaxies in redshift-space
• Stellar Populations and Galaxy Morphology at High Redshift

Cited by in corpus (12)

• Inhomogeneous cosmological models: exact solutions and their applications
• Establishing homogeneity of the universe in the shadow of dark energy
• The Cosmic Microwave Background in an Inhomogeneous Universe - why void models of dark energy are only weakly constrained by the CMB
• Obtaining the spacetime metric from cosmological observations
• The Mass of the Cosmos
• Determining the metric of the Cosmos: stability, accuracy, and consistency
• The Metric of the Cosmos from Luminosity and Age Data
• The Lemaitre Model and the Generalisation of the Cosmic Mass
• Solving the Observer Metric
• Calculating Observables in Inhomogeneous Cosmologies I: General Framework
• Towards the geometry of the universe from data
• Finding a Spherically Symmetric Cosmology from Observations in Observational Coordinates -- Advantages and Challenges