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Cosmological string models from Milne spaces and SL(2,Z) orbifold

The $n+1$-dimensional Milne Universe with extra free directions is used to construct simple FRW cosmological string models in four dimensions, describing expansion in the presence of matter with $p=k \rho $, $k=(4-n)/3n$. We then consider the n=2 case and make SL(2,Z) orbifold identifications. The m...

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Autor principal: Russo, J G
Lenguaje:eng
Publicado: 2003
Materias:
Acceso en línea:https://dx.doi.org/10.1142/S0217732304013209
http://cds.cern.ch/record/615324
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author Russo, J G
author_facet Russo, J G
author_sort Russo, J G
collection CERN
description The $n+1$-dimensional Milne Universe with extra free directions is used to construct simple FRW cosmological string models in four dimensions, describing expansion in the presence of matter with $p=k \rho $, $k=(4-n)/3n$. We then consider the n=2 case and make SL(2,Z) orbifold identifications. The model is surprisingly related to the null orbifold with an extra reflection generator. The study of the string spectrum involves the theory of harmonic functions in the fundamental domain of SL(2,Z). In particular, from this theory one can deduce a bound for the energy gap and the fact that there are an infinite number of Kaluza-Klein excitations with a finite degeneracy. We discuss the structure of wave functions and give examples of physical winding states becoming light near the singularity.
id cern-615324
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2003
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spelling cern-6153242019-09-30T06:29:59Zdoi:10.1142/S0217732304013209http://cds.cern.ch/record/615324engRusso, J GCosmological string models from Milne spaces and SL(2,Z) orbifoldParticle Physics - TheoryThe $n+1$-dimensional Milne Universe with extra free directions is used to construct simple FRW cosmological string models in four dimensions, describing expansion in the presence of matter with $p=k \rho $, $k=(4-n)/3n$. We then consider the n=2 case and make SL(2,Z) orbifold identifications. The model is surprisingly related to the null orbifold with an extra reflection generator. The study of the string spectrum involves the theory of harmonic functions in the fundamental domain of SL(2,Z). In particular, from this theory one can deduce a bound for the energy gap and the fact that there are an infinite number of Kaluza-Klein excitations with a finite degeneracy. We discuss the structure of wave functions and give examples of physical winding states becoming light near the singularity.hep-th/0305032oai:cds.cern.ch:6153242003-05-05
spellingShingle Particle Physics - Theory
Russo, J G
Cosmological string models from Milne spaces and SL(2,Z) orbifold
title Cosmological string models from Milne spaces and SL(2,Z) orbifold
title_full Cosmological string models from Milne spaces and SL(2,Z) orbifold
title_fullStr Cosmological string models from Milne spaces and SL(2,Z) orbifold
title_full_unstemmed Cosmological string models from Milne spaces and SL(2,Z) orbifold
title_short Cosmological string models from Milne spaces and SL(2,Z) orbifold
title_sort cosmological string models from milne spaces and sl(2,z) orbifold
topic Particle Physics - Theory
url https://dx.doi.org/10.1142/S0217732304013209
http://cds.cern.ch/record/615324
work_keys_str_mv AT russojg cosmologicalstringmodelsfrommilnespacesandsl2zorbifold