COT3 - Inhomogeneous Cosmology |
Speaker_ |
Hellaby, Charles |
Co-autors |
Hui-Ching Lu |
Talk _ |
The Mass and the Geometry of the Cosmos |
Abstract _ |
As the cosmological data generated by redshift surveys becomes increasingly accurate, the proper reduction and interpretation of the high redshift data will require knowledge of the cosmic geometry that is traveled through by the light rays we observe. It will no longer be necessary to assume homogeneity, the data will make it possible to quantify the level of homogeneity on different scales. The ultimate application of Einstein’s field equations is to determine the relation between matter and geometry in the real universe. A set of observations of the redshifts, angular diameters, and apparent luminosities of galaxies, as well as their number counts, combined with knowledge of their true diameters, luminosities and masses, plus the cosmic equation of state, can be turned into metric information. Though much theoretical development has been done, the proposed methods have never been implemented, so the 2 key issues of choosing appropriate numerical methods and handling real observational data have not been addressed. A preliminary numerical reduction scheme has been written and tested. The methods and difficulties encountered will be discussed. The locus where the past null cone crosses the apparent horizon has significant theoretical, numerical and observational properties. It allows us to determine a characteristic mass of the cosmos that is quite model independent. |