منابع مشابه
Duality and Strings, Space and Time
Duality symmetries in M–theory and string theory are reviewed, with particular emphasis on the way in which string winding modes and brane wrapping modes can lead to new spatial dimensions. Brane world-volumes wrapping around Lorentzian tori can give rise to extra time dimensions and in this way dualities can change the number of time dimensions as well as the number of space dimensions. This s...
متن کاملTime and space dependent backgrounds from nonsupersymmetric strings
We investigate maximally symmetric backgrounds in nonsupersymmetric string vacua with D-branes and O-planes localized in the compact space. We find a class of solutions with a perturbative string coupling constant in all regions of spacetime. Depending on the particular model, we find either a time evolution with a big-bang type singularity or a space dependent background with generically orbif...
متن کاملNon-Abelian Gerbes from Strings on a Branched Space-Time
As superstring solitons that carry Neuveu–Schwarz charge can be described in terms of gerbes, one expects non-Abelian gerbes to appear e.g. in the exotic six-dimensional world-volume theories of coinciding NS5 branes. We consider open bosonic strings on a space-time that is branched in such a way that the B-field is provided with the same Lie algebra structure as the world-volume gauge field on...
متن کاملNon-Critical Strings in Robertson-Walker Space Time
I consider a D+1 dimensional nonlinear σ model based on a possible interpretation of the Liouville field as a physical time. The Weyl invariance of this theory gives us restrictions for the background fields and the parameters of the theory, e.g. for trivial background one obtains the known regions for the dimension of the space-time (≤1 or ≥25). For a Robertson-Walker space time a special solu...
متن کاملCosmic strings in a space-time with positive cosmological constant
We study Abelian strings in a fixed de Sitter background. We find that the gauge and Higgs fields extend smoothly across the cosmological horizon and that the string solutions have oscillating scalar fields outside the cosmological horizon for all currently accepted values of the cosmological constant. If the gauge to Higgs boson mass ratio is small enough, the gauge field function has a power-...
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ژورنال
عنوان ژورنال: Annals of the Japan Association for Philosophy of Science
سال: 1993
ISSN: 0453-0691,1884-1228
DOI: 10.4288/jafpos1956.8.121