Kinematic Quadrupole Correction of CBR Anisotropies and Local Collapse
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**Session 71 -- Galaxy and CBR Distribution**
*Display presentation, Friday, January 14, 9:30-6:45, Salons I/II Room (Crystal Gateway)*

## [71.16] Kinematic Quadrupole Correction of CBR Anisotropies and Local Collapse

*Li-Zhi Fang (Steward Obs., Univ. of Aeriz), Xiang-Ping Wu (DAEC, Obs. de Paris-Meudon)*

In order to find the cosmic amplitude of the CBR quadrupole at the surface
of last scattering, the kinematic quadrupole correction of the CBR
anisotropies, $(\Delta {\sf T}/{\sf T})_q=(\Delta {\sf T}/{\sf T})_d^2/2$,
is usually applied to remove the contamination of the quadrupole produced
by local density inhomogeneities. Using an exact solution of the
CBR anisotropy produced by a local collapse described by a spherical
over-dense region embedded in a flat universe, we have found that the
quadrupole of local collapse origin cannot always be approximately
described by the kinematic quadrupole. Our numerical result shows that the difference between the kinematic and local quadrupoles depends on the
size and matter density in the peculiar field, and the position of
the observer. For a given dipole, the local quadrupole can be different
from the kinematic quadrupole by a factor as large as 3. Therefore, the kinematic quadrupole correction remains an uncertain factor in the
determination of the amplitude of a cosmic quadrupole. Nevertheless, a preliminary analysis shows that this uncertainty might not dramatically
change the cosmological origin of the COBE-DMR's quadrupole, unless
a huge peculiar gravitational field is assumed.

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