Anisotropic Observations in Universes with Nonlinear Inhomogeneity

We calculate the off--center observational relations in a sphericallysymmetric dust universe that is inhomogeneous at small redshifts. In contrastto the usual model, in which the CMBR dipole is interpreted as a Doppler effectdue to peculiar velocity, our model explores an alternative interpretation, inwhich the CMBR dipole is non--Doppler, and the observer is comoving with themean matter flow. We do not assume a background frame relative to whichpeculiar velocities are calculated. Our analysis is fully nonlinear and thedensity contrast is not assumed to be small. We obtain exact expressions forthe Hubble and deceleration parameters, and find that both parameters havequadrupole anisotropies, but no dipoles. A simple numerical procedure forcalculating the CMBR dipole anisotropy in our model is presented, and theobserved 0.1% dipole is shown to be reproducible with a reasonable choices ofparameters.Comment: 12 pages, Latex, 2 Maple graphs available from authors; submitted Ap