426 research outputs found
Renormalized Newtonian Cosmic Evolution with Primordial Non-Gaussianity
We study Newtonian cosmological perturbation theory from a field theoretical
point of view. We derive a path integral representation for the cosmological
evolution of stochastic fluctuations. Our main result is the closed form of the
generating functional valid for any initial statistics. Moreover, we extend the
renormalization group method proposed by Mataresse and Pietroni to the case of
primordial non-Gaussian density and velocity fluctuations. As an application,
we calculate the nonlinear propagator and examine how the non-Gaussianity
affects the memory of cosmic fields to their initial conditions. It turns out
that the non-Gaussianity affect the nonlinear propagator. In the case of
positive skewness, the onset of the nonlinearity is advanced with a given
comoving wavenumber. On the other hand, the negative skewness gives the
opposite result.Comment: 12 pages, 2 figure
Systematic solution-generation of five-dimensional black holes
Solitonic solution-generating methods are powerful tools to construct
nontrivial black hole solutions of the higher-dimensional Einstein equations
systematically. In five dimensions particularly, the solitonic methods can be
successfully applied to the construction of asymptotically Minkowski spacetimes
with multiple horizons. We review the solitonic methods applicable to
higher-dimensional vacuum spacetimes and present some five-dimensional examples
derived from the methods.Comment: Invited review for Prog. Theor. Phys. Suppl., 33 pages, 13 figures.
v2: References added v3: published versio
Orthogonal black di-ring solution
We construct a five dimensional exact solution of the orthogonal black
di-ring which has two black rings whose -rotating planes are orthogonal.
This solution has four free parameters which represent radii of and speeds of
-rotation of the black rings. We use the inverse scattering method. This
method needs the seed metric. We also present a systematic method how to
construct a seed metric. Using this method, we can probably construct other
solutions having many black rings on the two orthogonal planes with or without
a black hole at the center.Comment: 13 pages, 5 figures
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