Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First Observational Tests of Eternal Inflation   The eternal inflation scenario predicts that our observable universe resides
inside a single bubble embedded in a vast inflating multiverse. We present the
first observational tests of eternal inflation, performing a search for
cosmological signatures of collisions with other bubble universes in cosmic
microwave background data from the WMAP satellite. We conclude that the WMAP
7-year data do not warrant augmenting LCDM with bubble collisions, constraining
the average number of detectable bubble collisions on the full sky to be less
than 1.6 at 68% CL. Data from the Planck satellite can be used to more
definitively test the bubble collision hypothesis.

32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph