4 papers
Observable Quantities in Cosmological Models with Strings
Mariusz P. Dabrowski, Jerzy Stelmach
The Friedman equation for the universe with arbitrary curvature , filled with mutually noninteracting pressureless dust, radiation, cosmological constant, and strin…
Is Supernovae Data in Favour of Isotropic Cosmologies?
Mariusz P. Dabrowski
Most of the observational claims in cosmology are based on the assumption that the universe is isotropic and homogeneous so they essentially test different types of Friedmann model…
Perturbative String Dynamics Near the Photon Sphere
Mariusz P. Dabrowski, Alexander A. Zheltukhin
String dynamics near the photon sphere in Schwarzschild spacetime is considered on the basis of a perturbative approach with respect to a rescaled string tension as a small paramet…
String Cosmology and Chaos
John D. Barrow, Mariusz P. Dabrowski
We investigate Bianchi type IX ''Mixmaster'' universes within the framework of the low-energy tree-level effective action for string theory, which (when the ''stringy'' 2-form axio…