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               <dc:title>Bubble fluctuations in Omega less than 1 inflation</dc:title>
               <dc:creator>Garriga Torres, Jaume</dc:creator>
               <dc:subject>Teoria de camps (Física)</dc:subject>
               <dc:subject>Ones gravitacionals</dc:subject>
               <dc:subject>Field theory (Physics)</dc:subject>
               <dc:subject>Gravitational waves</dc:subject>
               <dc:description>In the context of the open inflationary universe, we calculate the amplitude of quantum fluctuations which deform the bubble shape. These give rise to scalar field fluctuations in the open Friedmann-Robertson-Walker universe which is contained inside the bubble. One can transform to a new gauge in which matter looks perfectly smooth, and then the perturbations behave as tensor modes (gravitational waves of very long wave-length). For &#xd;
(&#xd;
1&#xd;
−&#xd;
Ω&#xd;
)&#xd;
≪&#xd;
1&#xd;
, where &#xd;
Ω&#xd;
 is the density parameter, the microwave temperature anisotropies produced by these modes are of order &#xd;
δ&#xd;
T&#xd;
T&#xd;
∼&#xd;
H&#xd;
(&#xd;
R&#xd;
0&#xd;
μ&#xd;
l&#xd;
)&#xd;
−&#xd;
1&#xd;
2&#xd;
(&#xd;
1&#xd;
−&#xd;
Ω&#xd;
)&#xd;
l&#xd;
2&#xd;
. Here, &#xd;
H&#xd;
 is the expansion rate during inflation, &#xd;
R&#xd;
0&#xd;
is the intrinsic radius of the bubble at the time of nucleation, &#xd;
μ&#xd;
 is the bubble wall tension, and &#xd;
l&#xd;
 labels the different multipoles (&#xd;
l&#xd;
>&#xd;
1&#xd;
). The gravitational back reaction of the bubble has been ignored. In this approximation, &#xd;
G&#xd;
μ&#xd;
R&#xd;
0&#xd;
≪&#xd;
1&#xd;
, and the new effect can be much larger than the one due to ordinary gravitational waves generated during inflation (unless, of course, &#xd;
Ω&#xd;
 gets too close to 1, in which case the new effect disappears).</dc:description>
               <dc:date>2010-05-06T08:53:49Z</dc:date>
               <dc:date>2010-05-06T08:53:49Z</dc:date>
               <dc:date>1996</dc:date>
               <dc:type>info:eu-repo/semantics/article</dc:type>
               <dc:type>info:eu-repo/semantics/publishedVersion</dc:type>
               <dc:relation>Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.54.4764</dc:relation>
               <dc:relation>Physical Review D, 1996, vol. 54, núm. 8, p. 4764-4769</dc:relation>
               <dc:relation>http://dx.doi.org/10.1103/PhysRevD.54.4764</dc:relation>
               <dc:rights>(c) The American Physical Society, 1996</dc:rights>
               <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
               <dc:publisher>The American Physical Society</dc:publisher>
               <dc:source>Articles publicats en revistes (Física de la Matèria Condensada)</dc:source>
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