Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Limits on the Primordial Fluctuation Spectrum Void Sizes and CMBR
  Anisotropy   We suggest to use the common appearance of voids with a scale of $5000 \kms$
in the galaxy distribution to estimate the power spectrum on this scale. We use
a simple model for a gravitational formation of voids and we compare the
results with the matter fluctuations as constrained by the CMBR observations of
COBE. We find that a power spectrum $P(k)\propto k^n$ with $n \approx 1.25$ is
compatible both with COBE and with gravitational growth of large voids in an
$\Omega=1$ universe. A Harrison-Zel'dovich spectrum, $n=1$, normalized to
produce the observed CMBR fluctuations, does not have enough power for
gravitational growth of voids with a diameter of $5000 \kms$ in an $\Omega=1$
Universe. Such a spectrum would be compatible if (i) void diameters are smaller
($3500 \kms$), the voids are shallower or if the voids are rare (we assume that
the universe is void filled); (ii) $\Omega < 1$ i.e. the Universe is open;
(iii) galaxies do not trace matter on very large scale or if (iv) the voids do
not grow gravitationally.

15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th