Cosmology with Two Compactification Scales
نویسندگان
چکیده
منابع مشابه
Cosmology, cohomology, and compactification
Ashtekar and Samuel have shown that Bianchi cosmological models with compact spatial sections must be of Bianchi class A. Motivated by general results on the symmetry reduction of variational principles, we show how to extend the Ashtekar-Samuel results to the setting of weakly locally homogeneous spaces as defined, e.g., by Singer and Thurston. In particular, it is shown that any mdimensional ...
متن کاملCosmology with varying scales and couplings
The time variation of fundamental mass scales can have profound cosmological implications. We investigate a particular model of crossover quintessence which is compatible with all present cosmological observations. This model can also reconcile the reported time variation of the fine structure constant from quasar absorption lines with the bounds from archeo-nuclear physics and tests of the equ...
متن کاملThird Quantization of Kaluza-Klein Cosmology and Compactification
We study on the third quantization of a Kaluza-Klein toy model. In this model time (x) is defined by the scale factor of universe, and the space coordinate (y) is defined by the ratio of the scales of the ordinary space and the internal space. We calculate the number density of the universes created from nothing and examine whether the compactification can be explained statistically by the idea...
متن کاملDynamical Topology Change, Compactification and Waves in String Cosmology
Exact string solutions are presented, where moduli fields are varying with time. They provide examples where a dynamical change of the topology of space is occurring. Some other solutions give cosmological examples where some dimensions are compactified dynamically or simulate pre-big bang type scenarios. Some lessons are drawn concerning the region of validity of effective theories and how the...
متن کاملbrane - world compactification , black hole thermodynamics and holographic cosmology with R 2 terms
We present a linear treatment of the Einstein-Gauss-Bonnet gravity on a singular co-dimension one brane embedded in (d + 1) dimension anti-de Sitter spacetimes. We exhibit that the zero-energy solution corresponds to the localized massless graviton on the brane with correct momentum and tensor structures. By introducing the higher curvature terms in quadratic form, we consider a braneuniverse i...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Chinese Physics Letters
سال: 2000
ISSN: 0256-307X,1741-3540
DOI: 10.1088/0256-307x/17/4/028