<?xml version="1.0" encoding="UTF-8"?>
<tape xmlns="http://library.lanl.gov/2005-01/STB-RL/tape/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://library.lanl.gov/2005-01/STB-RL/tape/ http://purl.lanl.gov/STB-RL/schemas/2005-01/tape.xsd"><tape-record><tape-record-admin><identifier>oai:arXiv.org:hep-th:0208181</identifier><date>2005-06-01T14:36:10Z</date><record-admin></record-admin></tape-record-admin><record>
 <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
 <dc:title>Complex singularities of the critical potential in the large-N limit</dc:title>
 <dc:creator>Meurice, Y.</dc:creator>
 <dc:description>  We show with two numerical examples that the conventional expansion in powers
of the field for the critical potential of 3-dimensional O(N) models in the
large-N limit, does not converge for values of phi^2 larger than some critical
value. This can be explained by the existence of conjugated branch points in
the complex phi^2 plane. Pade approximants [L+3/L] for the critical potential
apparently converge at large phi^2. This allows high-precision calculation of
the fixed point in a more suitable set of coordinates. We argue that the
singularities are generic and not an artifact of the large-N limit. We show
that ignoring these singularities may lead to inaccurate approximations.
</dc:description>
 <dc:description>Comment: 9 pages, 9 figures, uses revtex</dc:description>
 <dc:date>2002-08-25</dc:date>
 <dc:type>text</dc:type>
 <dc:identifier>http://arXiv.org/abs/hep-th/0208181</dc:identifier>
 </oai_dc:dc>
</record></tape-record><tape-record><tape-record-admin><identifier>oai:arXiv.org:hep-th:0208182</identifier><date>2005-06-01T14:40:35Z</date><record-admin></record-admin></tape-record-admin><record>
 <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
 <dc:title>Virasoro Algebra for Particles with Higher Derivative Interactions</dc:title>
 <dc:creator>Ho, Pei-Ming</dc:creator>
 <dc:description>  In this paper we show that the worldline reparametrization for particles with
higher derivative interactions appears as a higher dimensional symmetry on the
phase space. In the limit of infinite order time dervatives, the fields on the
worldline get naturally promoted to those living on a two dimensional space,
and the reparametrization symmetry is locally the same as the conformal
symmetry.
</dc:description>
 <dc:description>Comment: 11 pages</dc:description>
 <dc:date>2002-08-25</dc:date>
 <dc:type>text</dc:type>
 <dc:identifier>http://arXiv.org/abs/hep-th/0208182</dc:identifier>
 </oai_dc:dc>
</record></tape-record><tape-record><tape-record-admin><identifier>oai:arXiv.org:hep-th:0208183</identifier><date>2005-06-01T14:36:10Z</date><record-admin></record-admin></tape-record-admin><record>
 <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
 <dc:title>Generalized Bogoliubov Transformation for Confined Fields: Applications
 in Casimir Effect</dc:title>
 <dc:creator>Silva, J. C. da</dc:creator>
 <dc:creator>Khanna, F. C.</dc:creator>
 <dc:creator>Neto, A. Matos</dc:creator>
 <dc:creator>Santana, A. E.</dc:creator>
 <dc:description>  The Bogoliubov transformation in thermofield dynamics, an operator formalism
for the finite-temperature quantum-field theory, is generalized to describe a
field in arbitrary confined regions of space and time. Starting with the scalar
field, the approach is extended to the electromagnetic field and the
energy-momentum tensor is written via the Bogoliubov transformation. In this
context, the Casimir effect is calculated for zero and non-zero temperature,
and therefore it can be considered as a vacuum condensation effect of the
electromagnetic field. This aspect opens an interesting perspective for using
this procedure as an effective scheme for calculations in the studies of
confined fields, including the interacting fields.
</dc:description>
 <dc:description>Comment: 20 pages, latex(article)</dc:description>
 <dc:date>2002-08-25</dc:date>
 <dc:type>text</dc:type>
 <dc:identifier>http://arXiv.org/abs/hep-th/0208183</dc:identifier>
 </oai_dc:dc>
</record></tape-record><tape-record><tape-record-admin><identifier>oai:arXiv.org:hep-th:0208187</identifier><date>2005-06-03T13:23:30Z</date><record-admin></record-admin></tape-record-admin><record>
 <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
 <dc:title>Branes in Time-Dependent Backgrounds and AdS/CFT Correspondence</dc:title>
 <dc:creator>Alishahiha, Mohsen</dc:creator>
 <dc:creator>Parvizi, Shahrokh</dc:creator>
 <dc:description>  We study supergravity solutions of Dp-branes in the time-dependent orbifold
background. We show that worldvolume theories decouple from the bulk gravity
for p less than six. Along AdS/CFT correspondence, these solutions could
provide the gravity description of noncommutative field theory with
time-dependent noncommutative parameter. Type II NS5-brane (M5-brane) in the
presence of RR n-form for n=0,..., 4 (C field) in this time-dependent
background have also been studied.
</dc:description>
 <dc:description>Comment: 15 pages, latex file, v2: typos corrected, ref added</dc:description>
 <dc:date>2002-08-26</dc:date>
 <dc:date>2002-08-27</dc:date>
 <dc:type>text</dc:type>
 <dc:identifier>http://arXiv.org/abs/hep-th/0208187</dc:identifier>
 </oai_dc:dc>
</record></tape-record><tape-record><tape-record-admin><identifier>oai:arXiv.org:hep-th:0208188</identifier><date>2005-06-03T13:23:30Z</date><record-admin></record-admin></tape-record-admin><record>
 <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
 <dc:title>On T-Duality in Brane Gas Cosmology</dc:title>
 <dc:creator>Boehm, Timon</dc:creator>
 <dc:creator>Brandenberger, Robert</dc:creator>
 <dc:description>  In the context of homogeneous and isotropic superstring cosmology, the
T-duality symmetry of string theory has been used to argue that for a
background space-time described by dilaton gravity with strings as matter
sources, the cosmological evolution of the Universe will be nonsingular. In
this Letter we discuss how T-duality extends to brane gas cosmology, an
approximation in which the background space-time is again described by dilaton
gravity with a gas of branes as a matter source. We conclude that the arguments
for nonsingular cosmological evolution remain valid.
</dc:description>
 <dc:description>Comment: 7 pages, no figures</dc:description>
 <dc:date>2002-08-26</dc:date>
 <dc:type>text</dc:type>
 <dc:identifier>http://arXiv.org/abs/hep-th/0208188</dc:identifier>
 </oai_dc:dc>
</record></tape-record></tape>