Topology and Singularities in Cosmological Spacetimes Obeying the Null Energy Condition
نویسندگان
چکیده
منابع مشابه
Cosmological singularities in Bakry–Émery spacetimes
We consider spacetimes consisting of a manifold with Lorentzian metric and a weight function or scalar field. These spacetimes admit a Bakry–Émery–Ricci tensor which is a natural generalization of the Ricci tensor. We impose an energy condition on the Bakry–Émery–Ricci tensor and obtain singularity theorems of a cosmological type, both for zero and for positive cosmological constant. That is, w...
متن کاملNull weak singularities in plane-symmetric spacetimes
We construct a new class of plane-symmetric solutions possessing a curvature singularity which is null and weak, like the spacetime singularity at the Cauchy horizon of spinning (or charged) black holes. We then analyse the stability of this singularity using a rigorous non-perturbative method. We find that within the framework of (linearly-polarized) plane-symmetric spacetimes this type of nul...
متن کاملNull cosmological singularities and free strings
We continue exploring free strings in the background of null Kasner-like cosmological singularities, following arXiv:0904.4532 [hep-th]. We study the free string Schrodinger wavefunctional along the lines of arXiv:0807.1517 [hep-th]. We find the wavefunctional to be nonsingular in the vicinity of singularities whose Kasner exponents satisfy certain relations. We compare this with the descriptio...
متن کاملString spectra near some null cosmological singularities
We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyse string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can be solved for exactly in these time-de...
متن کاملIsotropic Cosmological Singularities I. Polytropic Perfect Fluid Spacetimes
We consider the conformal Einstein equations for 1 ≤ γ ≤ 2 poly-tropic perfect fluid cosmologies which admit an isotropic singularity. For 1 < γ ≤ 2 it is shown that the Cauchy problem for these equations is well-posed, that is to say that solutions exist, are unique and depend smoothly on the data, with data consisting of simply the 3-metric of the singularity. The analogous result for γ = 1 (...
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: Communications in Mathematical Physics
سال: 2017
ISSN: 0010-3616,1432-0916
DOI: 10.1007/s00220-017-3020-9